American Journal of Computational Linguistics 
Mi crof i che 62 
EXPLAlATION CAPABILITIES 
OF PRODUCTION -BASED CONSULTATION SYSTEMS 
A. CARLISLE SCOTT, WILLIAM J. CLANCEY, 
RANDALL DAVIS, AND EDWARD H. SHORTLIFFE 
Research sponsored in part by Bureau of Health Services Research 
and Evaluation, Grant HS01544; Biotechnology eResources, Grant 
RR-00785; Advanced Research Projects Agency, ARPA Contract DAHC- 
15-73-C-0435; National Institute of Health, Grant GM-01922. 
Copyrzght Q 1977 
Association for Computational Ginguistics 
A computer program that models an expert in a given domain fa more 
likely to be accepted by experts in that domain, and by non-experts seeking 
it9 advice, if the system can explain its actions. An explanation 
capability not only adds to the system s credibility, but also enables the 
non-expert user to learn from it. Furthermore, clear explanations allow an 
expert to cbeck the system's "reasoninqfl, possibly discovering the need for 
refinesents and additions to the system s knowledge baseu In a developinq 
system, an explanation capabilitv can be used as a debuq~lnq aid to verify 
that additions to the system are worckins as thev should, 
Thls paper dixusses the general characterlstlcs of explanation 
systems. what types of explanablons thev should be able to give, what types 
of  nowl ledge will be needed in order to give these explanabiohs, and how 
thls knowledge mlqht be oraanlzed. The ex~lanation fae ~lltv In MYCIN 
[5,6,7] is discussed as an 11lustrakion of how the various pnoblems miqht be 
approached. 
Table of Contents 
Sect ion 
Subsec tlon 
Pane 
General Discussion . ... . . . . • . 4 
1 .I Consultat-ive Production Systems . 9 . . . . 4 
1.2 Performance Character lstics of an Ex~lanation 
Ca~abi1i.t~ . . . . . . . . . . I . . . 7 
1.3 Knowledge Requirements of an Explanation Ca~abilitv . . -9 
1.4 Program Design Considerations . o . I . . . . . . 12 
An Example -- MYCIN . .*... . . e . . 16 
2.1 Overv lew . . . . . . . . . . . . - 16 
2.2 Organization of Knowledge in MYCIN . . - . 9 . 19 
2.3 Scope of MYCIN'S Explanation Capability . . rn . . 25 
2.4 Understanding The Questlon . . . . . . . . . - 30 
2.5 Answering the Question . . . . . . . . 36 
Conclusions . . . . . . . . . . I I . 48 
1 General Discussion 
1.1 Consultative Production Systems 
A consultation proqram plays the mle of an expert consultant in 
some domain, ~ivin~ advice or answers to non-experts with ~roblems in the 
domain. Users will often want to know how the svstea arrived at its results 
durinq a particular consultation. This Daper explalns how the 
implementation of such a proqram as a ~rod~ction system can fac~lltate 
program-generated ex~lanations. 
A production system [2] consists of three basic components. a set of 
production rules, a data base which is both used and updated bv these rules, 
and a rule interpreter. A production rule often is in the form of a 
situation-action rule. it describes a situation and a set of actions to be 
taken if tbis situation is found to exist. The rule intermeter deternines 
the order In which rules will be tried, checks to see if the situations 
exist, and undertakes the required actions. It also determines how manv of 
the potentially useful rules wjll be used. only the flrst (where orderinq 
may be predetermined or comouted dynamically), all possible rules, or enough 
rules to satisfy some criterion that the interpreter uses. 
In some production systems, rules are always trled in a 
predetermined order. In others, the order in which rules are tried varies 
with different consultations, since a rule will be tried as soon as the rule 
interpreter determines that it may be useful. In such svsteas, the common 
alternatives are data-directed rule invocation, in which a rule is 
considered "usefulff if its situation part matches the data base, and qoal- 
directed rule invocation, in which a rule is if its action part 
will help the system reach its current goal. Many systems use a combination 
of soal- and data-directed rule invocation. 
A consultative production system need not be a psycholoqical model, 
imitating a human s reasoning process. The imporbant point is that the 
System and a human expert use the same (or similar) knowledqe about the 
domain to arrive at the same answer to a given problem. The svstem's rules 
and data base can be viewed as a knowledge base containinq the domain- 
speclfic knowledge of an expert as well as facts about a particular broblem. 
When a rule is used, its actlons make changes to the data base which are the 
sy5tem's decisions or deductions. Thus, a rule can be thouqht of as a plece 
of judgmental knowledqe, using the judqment and knowledge of au expert to 
make deductions. 
The process of trying rules and taking actlons can be thouqht of as 
llreasonsngw, and explanations consist of showing how rules used information 
provided by the user to make various intermediate de~uctions and finally to 
arrive at the answer. If the information contained in these rules is 
sufficient to show why an action was taken (without aettinq into programming 
details), an explanation can conslst of printing each rule that was used (or 
an Engllsh equivalent of what the rule means,) 
EXPLANATION 
' 
CAPABILITY 
PRODUCTION RULES 
Judqmental Knowled~e 
about domain 
General Factual 
Knowledge of 
domain 
Figure 1. A Production-Based Consultation System 
with Explanation Capability 
The three coniponents of a production system (a 
RULE INTERPRETER, a set of PRODUCTION RULES, and a DATA 
BASE 1 are augmented by an EXPLANATION CAP4BILITY. The 
data base is made up of general facts about the system's 
domain of expertise, facts that the user enters about a 
specific problem, and deductions made about the problem 
by the system's rules. These deductions form the basis 
of the syst en's consultative advice. 
The explanation capability makes use of the 
system's knowled_qe base to qive the user explanations. 
This knowledae base is made UD of static 
domain-specif ic knowledge ( both factual and jud mental) 
and dynamf,~ knowledge specific to a particular problem' 
1.2 
Performance Characteristics of an Explanation Capability 
The purpose of an explanation ca~abilitv (KC) is to qive the user 
access to as much of the system s knowledge as posbible. 
Ideally, it should 
be easy for a user to get a complete, understandable answer to anv 
sort of 
question about the system's knowledge and  pera at ion -- both in general, and 
with reference to a particular consultation. 
This llplies three major goals 
in the development of an explanation capability. 
1) 
To ensure that the EC can handle questions about all 
relevant aspects of the system'$ knowledge and actions. It 
should be capable of giving a few baslo types of 
explanations, for example. 
How it made a certain decision 
How it used a piece of information 
What decision ~t made about aome subproblem 
Why it didn t use a certain plece of information 
Why it failed to ma!ce a certain decision 
Why it required a certain piece of infornatlon 
Why it didn t require a certain ~iece of information 
How it will find out a certain plece of Information 
[while tRe consultatinn is in oroqress] 
What the system is currently doing? [while the 
consultation is in ~roaress] 
The mecific set of explanation types which are chosen as 
basics, however, will depend on the particular system. 
2) To enable the user to get an explanation which 
answers the question completely and comprehensively. 
3) 
To make the EC easy to use. A novice should be able 
to use the EC without first spending a large amount of time 
lehrninq how to request explanations. 
We will distinguish two slighfly different functions for an EC and 
divide it into two components. the reasoning-status checker (RSC) to be used 
during the consultation, and the general question answerqr (GQA) to be used 
during the consultation or after the system has ~rinted its results. 
A reasoning-status checker will answer questions asked durinq-a 
consultation about the status of the systsb s reasoning process, A few 
simple commands are often sufficient to handle the questions that the RSC is 
expected to answen 
A genera question-answer will answer questions about the current 
state of the syqtem s knowledge base, including both static domain 
khdwledge and facts accumulated duainq the consultation. A GQA will often 
need the ability to recognize a wide range of question types about many 
aspects of the system's knowledge. For this reason, it might be difficult to 
define a few simple commands which would be easy to learn and still cover 
all the possible questions that might be asked. Consequently, natural- 
language processlnq in this component may be im~ortant to an explanation 
system s acce~tability. 
In an interactwe consultatlor!, the svstem periodically requests 
information about the problem. This offers the user an opportunity to 
request explanations while the consultation is in proaress. In non- 
interactive oonsultatlons, the user has no opportundtv to interact hith the 
system untll after lt has printed ~ts conclusions. Unless there 1s some 
mechanism allowing a user to interrupt the reasoning process and ask 
questions, the explanation capability for such a system will be limited to 
questions about the system's final knowledge state. It will have no 
reasoning-status checker, and its general. question-answerer will only be 
accessible at the termination of the consultatian . 
1.3 
Knowledge Requirements of an Explanation Capability 
An EC must know what is in the system's knowledge base, and how it 
is organized. In order to give explanations of the svstem's current (or 
previous) actions, an EC also needs to understand how the system s rule 
interpreter works. when ruces w~ll be tried how they can fall, what causes 
the interpreter to try one rule but not another etc. This qeneral "schemaw 
for how or why certain rules are used, toqether with a comprehensive record 
of the specific actions taken during a particular consultation, can be used 
a$ a basis fbr explaining the results of that cansultation. 
A reasoning-status checker will need d record of what the system has 
done so far in order to explain how it arr4ved at the current ste~. General 
knowledge bf how the rule interpreter works is necessary in order to explain 
where the current step wlll lead. The abllity to understand individual 
rules Also may be necessary to the extent that the content of a rule may 
explain why it was necessary to use this rule, or may affect which futupe 
rules will be trled. 
A general question-answerer will need more ~nfomatlon about the 
system since the scope of its explanations is much broader. its task is to 
answer general questions about Lhe system's knowledge base. To do this, it 
must know how the system stores knowledge about its area of expertise (the 
static kdowledge with which it starts each consultation) and how it stores 
facts gathered during a particular consultation (its dynamlc knowledge). 
These two types of information will allow a GQA to answer guestions about 
the substance and extent of the ~roduction system's current knowledge. 
If an explanation capability also is ta provide information about 
how the system arrived at the facts that are currently in its dynamic 
knowledge base, the GQA will need all the information that a reasoninp- 
status checker uses. a detailed record of the consultation, an understand in^ 
of the rule snterpreter, and the ability to understand rules. 
These three types of knowledge could be supplemented with a limited 
amount of qeneral information about such thinqs as elementary losic, set 
theory, and arithmetic comparisons. This would allow the GQA to answer more 
complicated questions about why the system's knowledge base IS inb its 
current state, and to answer questions involving pelationshi~s between 
different facts in the knowledge base. 
The nature of the consult'ation domain as well as what primarv 
purpose the explanation capability is to serve wlll influence the range of 
questions that an EC should handle. In some systems, a slm~le retrieval of 
facts may suffice, while others may need to give detailed description 01 the 
product ion system's ltdeclsionfl Drocess and to make a number of deductions 
from facts that it has. 
I 
KNOWLEDGE BASE OF CONSULTATION SYSTEM 
Knowledge Knowled~e 
I 
HISTORICAL KNOWLEDGE OF CONSULTATION 
Record of all deductions made during 
the c~nsultation 
i 
MISCELLANEOUS DOMAIN-INDEPENDENT 
KNOWLE!DGE 
I) 
PROCEDURAL KNOWLEDGE ABOUT THE 
CONSULTATION SYSTEY 
Knowledqe of Knowledqe of 
product ion 
interpreter 
i 
Figure 2. Knolwledge Requirements of an 
Explanation Capability 
Access to the consultation system's knowledge 
base is a prerequisite for performance of the 
explanation capabilltv. Other types of knowledqe 
may be added to the system to enable the EC to 
answer a wider range of questlona, 
L 
1.4 Program Deaign Considerations 
The last two sections described what an explanation capability is, 
butlininq what tasks it should perfom, and what it requires in order to 
per1 om these tasks, In thisl section, we discuss design considerations for 
the parent production system that will enable its EC to meet the 
requirements that were outlined in the previous section. This discussion is 
not meant to define the vcorrectw way of representing or organizing 
knowledge, but rather to mention certain factors which should be taken into 
account when declding what representation or orqanization will be best for a 
given product Ion system. 
1.4.1 Question Types 
The first step ~s to decide what basic types of questions the system 
should be able to answer. This will have a direct Influence on how the EC 
is im~lemented. It is important, however to make the rnitial desl~n 
flexible enough to accomodate possible future additions to the set of 
basics. 
If the basic forms are diverse enough, some level of natural- 
languaqe understanding may be necessary. The degree of sophlstlcation of 
the natural-languacze processor will depend won what kind of ~erformance is. 
expected of the EC 
1.4.2 Organization of Knowledge 
The format and organigation of various components of the production 
system's knowledge base will affect the deslgn of an EC. 
Individual ~ieces 
of static and dynamic knowledge presumably will be organized m some fashion 
which makes them accessible during the consultation. A GOA facility could 
make use of such organization 
to help In finding the information 
needed bo 
answer a question. The less organized the knowledge base the more 
difficult wxlf, be the task of the EC, as more complicated routines must be 
used in order to find the desired ~nformation. 
During the cQurse of the consultation, the system should keep a 
record of its actlons for use by both Co~nponents of the explanation 
capability. 
Where the ordering of events is important (e.~;. when the action 
of one rule establishes the situation necessary for a subsequent rule to 
yuuceed), the record should be structured in a madner which reflects the 
ordering of events as well as the reasons whv each event occurred. 
1.4.3 Knowledge of What Rules Mean 
The explanation capability will need to understand some of the 
semantics of indlvldual production rules. Thls requirement could be met by 
having the svstem's knowledge base include a description of what each Pule 
means, encoded in some form which would be of use to the EC. If the format 
of the system's rules is highly stylized and well-defined, however, it might 
be possible instead to implement a mechanism for 'Iread~ng" the rules. the 
language in which the rules themselves are written could be defined. A 
high-level description of the individual components of this language, 
telling what each component means, could be used to enable the EC to read 
and understand rules. If the rule set consists of a large nuaber of rules, 
and these rules are composed entirely of a relatively small number of 
primitive elements, this second approach has the advantage that less 
information needs ts be stored -- a description of each of the orimit~ve 
components, as opposed to a description of each rule. When new rules are 
added to the system, the first approach requires that descriptions of these 
rules must be added. With the second approach, provided that the new rules 
are made up of the standard rule components, no additional descriptite 
information would be needed by the explanation capabilitv. 
1.4.4 Knowledge of the Rule Interpreter 
Enabling an EC to understand how t,he rule interpreter works is 
analoqous to enabling lt to understand rules It must be able to "read" the 
interpreter or else it must have access to some stored description of how 
the interpreter works. ?here is a thirkl approach for understandlnq the rule 
interpreter, one whlch would not be feasible for understand in,^ a larse 
number of rules. Knowledge of how the interpreter works could be built into 
the EC -- the information would not be stated explicitly, but would be used 
implicitly by the programmer In writing the actual code for the explsnation 
capability. The EC can be thousht of as a number of ms~ec1a1ist3ff, each 
capable of glving a single type of explanation. There could he one 
specialist for each of the baslc questlon tv~es that the systen can answer. 
Each of the specialists needs only a small amount of ~nfomation about the 
rule interpreter whlch could be built Into ~ts ltexplalnln~n procrea. 
1.4.5 Other Domain-Independent Knowledge 
The final type of knowledge that some general quest~on-answering 
facilities wlll need is lnformatlon allowinq deductions to be vade froa 
facts In the knowledge base. The re~resentation and extent oC thls 
knowledge will depend upon the types of questions that the system is to 
answer If logic is needetl onlv to dete~mine the answers to questions of a 
certain tvpe for example, the necesaarv deductions could be built into the 
specialist for answerinq that type 
of question. On the other hand, in aowe 
explanation capibilities, the GQA will be expanded to do more than simply 
qive explanations of the system s actions or to query its data base -- it 
will be expected to answer a wide range of questions involvlnq various kinds 
sf inferences about the knowled~e base. Such a CQA will need to check for 
equality or set membership, make arithqetic compariSons, or make logical 
deductions. In general most information of this type can be embodied In a 
new kind of specialist which is an expert at some sort of logical deduction 
or comparison. Representation of this sort of qeneral knowled~e will become 
important as the GO4 becomes not sinlply an explanation tool, but also a 
deduct ive one. 
2 An Example -- MYCIN 
2.1 Overview 
MYCIN [5,6,7] is an example of a production-based consultation 
system with a well-developed explanation capability. A production run is an 
infectious disease therapy consultation in which MYCIN is the infectious 
dlseaae expert, and the user is a doctor who wants advice about the 
treatment of a patient. 
Knowledge that is gathered during the consultation is organized into 
attribute-object-value triples. In response to questions during the 
consultation, the user enters information about the existence of several 
objects, called contexts. the patient, infections that the patient has, 
organisms which may be causing these infections, cultures that were taken, 
and drugs that were qiven, The task of the consultation system is to 
determine the values of various attributes (called clinical ~arameters) of 
these contexts. For example, AGE is a clinical parameter of the patient; 
IDENTITY is a clinical parameter of an oreanism, with STRFPTOCOCCUS as a 
possible value; SITE is a parameter of a culture, with BLOOD as a possible 
value. 
A clinical parameter's value may be determined by asking the user, 
or by using decision rules. The parameter is said to be rvtracedw when the 
syBtem has done all it can to find out the parameter's value. Tracinq a 
parameter involves asking the user for a value (where applicable) and trying 
rules for determining the value of that parameter. Rules are tried until 
the value is known with certainty or there are no rules left to use. 
Each decision rule has a situatiorl part called its PREMISE. This 
con9ists of predicates, conditions that are tested to determine whether the 
indicated situation exists. If .the conditions in a rule's PREMISE are true, 
its ACTION will be evaluated, giving new (or updated) values to some 
parameter(s) . Before a aondrtion in a rule's PREMISE can be tested, the 
parameters that it mentions must be traced. For example, before rule 209 
(below) can succeed, the system must know the site of the culture, the 
portal of entry of the organism, and whether the patient is a compromised 
host. If any of the clauses in the PREMISE is false, or if the system is 
unable to find out the value of one of these parameters, the rule will fail. 
----111 
(PREMISE) If: 1) T@e site of the culture is blood, and 
2) 
The portal of entry of the organism is GI, and 
3) The patient is a compromised host 
(ACTION) Then: It 1s definlte (1 -0) that bacteroides is an organism 
for which therapy should cover 
Associated with each attribute-object-value triple is a certainty 
factor -- a number between -1 and 1 inclusive which indicates how stronqly 
the system belleves that the attribute of the object has the indicated 
value. The user nay modify the answer to any question with a certainty 
factor, and all rules make conclusions which specify a degree of oertainty 
as well as attribute, object, and value. 
Each context is named uniquely, allowing the system to refer to 
CULTURE-2, meaning the second culture, or ORGANISM-3, meaning the third 
organism. Moreover, the contexts are orqanized into a tree known as the 
context tree, which defines relationships among them. For example, an 
organism is the direct descendent of' the culture from whicl~ it was isolated. 
In the portion of a tree shown in FQure 3 ORGANISM-3 hangs under CULTUR'E-2 
indicatinq that STREPTOCOCCUS was isolated from the BLOOD culture. 
I NFECTION-2 
I 
INFECTION: PNEUMONIA 
WHENINFFCT: 2/6/76 
CULTURE-2 CU LTURE-3 
I SITE: BLOOD SITE: SPUTUM 
ORGAN ISM-3 
IDENTITY: STREPTOCOCCUS 
Figure 3. Portion of a Context Tree Showing Some 
Contexts, Clinical Parameters, 
and Values 
The rule interpreter (MYCIV'S control structure, described in detail 
in ['TI) choases the pules which should be used in the particular 
consultation, interprets these rules, and creates a record of ~ts actions 
for use by the explanation system. Rules are invoked to find out values of 
parameters in a given context. A rule is applied to the lowest context in 
the context tree whose parameters are mentioned by the rule. The rule can 
use (or conclude about) parameters of this context, or of anv context which 
1s its ancestor In the tree. For example, if RULE209 were apolied to 
ORGANISM-3 (see Figure 3) it would need the SITE of the culture from which 
the STREPTOCOCCUS was isolated. The tree indicates that this is CULTURE-2, 
Rather than being a sequential cycle throuqh the rule set, wher-e 
each rule is tried in some predetepmined order, the flow of control is qoal- 
directed. This means that only rules which conclllde about the current goal 
(to find out the value of a given parameter) are examined. The PREMISE of 
one of these rules may need to use some ~arameter whose value is unknown, 
This sets up a subgoal, namely to deterqine the value of this parameter so 
that the rule can be used. MYCIN's goal-direcrted approach means that the 
system (and not the user) takes the initiative during a consultation. The 
user will be asked about onLy those parameters Qhich way be relevant 
to the 
particular patient's case. 
2.2 
OrganizatYon of Knowledge in MYCXN 
In order to give explanations of a consultation system's decisions, 
an explanation capability must have access to the system's knowledge base. 
More informative emlanations can be given if the EC also has knowledae of 
how the syfitem works, a record of the consultation, and possibly some 
domain-independent knowledae. This section discusses how MYCIN meets these 
requirements. 
The system's knowledee base consf sts of static medical knowledge 
plus dynamic knowled3e about a specific consultation. Static knowledqe is 
further classified as factual and judgmental. Factual knowled~e consists of 
facts which are medically valid inde~endent of the ~ayticular case. 
Judgemental knowledge consists of product ion rules representing deduct ions 
which might be made, conditional an what is already known about the case. 
The format of production rules and of dynamic knowledge has already been 
described. 
2.2.3 Organization of Factual Knowledge 
As discussed in Section 2.1, all knowledge which is gathered durinq 
the consultation is organized into attribute-object-value triples. For 
consistency, many facts in the static knowledqe base also have this format. 
This includes objects such as bacteria and antibiotics, and attributes such 
as the staininrg characteristics of a bacterium or the recommended dosage of 
an antibiotic : 
ATTRIBUTE OBJECT VALUE 
------.I-- ------ ----- 
GRAM E .COLI GRAMNEG 
DOSE GENTAMICIN 1.7 mq kg q8h IV (or IM) 
The remainder of the factual knowledge consists of lists and tables: 
pieces of aedical knowledge, organized m such a way that they can be used 
to augment the producbion rules. For example, one such piece of knowledqe 
is the list of the possible culture sites which are normallv nonsterile, 
NONSTERILESITES : ( CERVIX CUTANEOUS-ULCER LOCHIA NOSE SKIN 
STOOL THROAT URETHRA VAGINA) 
The likely pathogens associated with the different culture sites are 
organized in a table, with different entries for the different sites, 
PATH-FLORA 
-------..-- 
THROAT : (STREPTOCOCCUS-PNEUMONIAE STREPTOCOCCUS- 
GROUP-A NEISSERI A-MENINGITIDIS ) 
URINE: (E.COLI PSEUDOMONAS ENTEROCOCCUS PROTEUS 
KLEBSIELLA ENTEROBACTER) 
SKIN : (STAPHYLOCOCCUS-COAG-POS STREPTOCOCCUS- 
GROUP-A STAPHYLOCOCCUS-COAG-NEG) 
CERVIX: ( STREPTOCOCCUS CLOST RIDIUM-GANGRENE 
NEISSERIA-GONORRHA STREPTOCOCCUS- 
GROUP-A ) 
Production rules can make use of this tabularized information: 
RULE058 
--"-I-- 
If: 1) The site of the culture is one of: those sites 
that are normally nonsterile, and 
2) This organism and at least one of the likely 
pathogens associated with the site of the culture 
agree wi'th respect to the following properties: 
gram morph air 
Then: There is strongly sugaestive evidence (.9) that 
each of these pathogens is the identitv of the 
organism 
Note that the information in the table could have been 0r~anized as 
attribute-object-value triples (where the object would be a culture site). 
If this had been done, however, the above rule could not have been written. 
To accomplish the same purpose (without a change in the control structure), 
the svstem would have needed several rules -- a separate one for each entry 
in the table. Structurinq certain facts into lists an.d tables er~ables 
individual production rules to exDress general theories which allow a number 
of specific deduct ions to be made. 
2.2.2 Procedural Knowledge 
Each of MYCIN'S approximately 400 rules is composed of a small 
number of conceptual primitives. 
A total of 60 such primitives make up the 
language in which rules &re written, This design facilitated the 
implementation of a mechanisp for translating rules into Enqliah (described 
in detail in 171). Each primitivs functions has a translation template with 
blanks to be filled in with translations of the function's arquments. A 
larrr;e part of MYCIN'S exolanation capabilitv depends on this ability to 
translate rules into a form that the user can understand. 
Having a small number of rule components also facilitates the 
examination of rules to see which might be apnlicable to the explanation at 
hand. MYCIN'S knowledge of production rules, therefore, takes the form of a 
general mechanlsrn for "readinq" rules, On the other hand, no attempt has 
been made to read the code of the rule interpreter. Procedural knowledge 
about the interpreter is embodied in nspecialistsu, epch capable of 
answerinq a single type of question. Each specialist knows how the relevant 
part of the control structure works and what pieces of knowledge it uses. 
In order to understand rules, the system's various specialists use a 
small amount of knowledge about rules in general, tosether with descriptions 
or templates of each of the rule components. As an example, the following 
rule is composed of the units SAND, SAME, and CONCLUDE. 
RULE009 
------- 
PREMISE: (SAND (SAME CNTXT GRAM GRAMNEG) 
(SAME CNTXT MORPH COCCUS)) 
ACTION : ( CONCLUDE CNTXT IDQNTITY NEISSERIA TALLY 800) 
[Translation: 
If: 1) The gram stain of the or~anism is qrarnneg, and 
2) 
The morphology of the organism is coccus 
Then: There is strongly suggestive (-8) that the identity 
of the orqanism is Neisseria] 
[When the rule is used, the LISP atom CNTXT is bound to 
some object, the context to which the rule is ap~lied 
(see Section 2.111 
The template for CONCLUDE is shown below. This describes each of the 
arguments to the function: first, an object (context); second, an attribute 
(clinical parameter); third, a value for this parameter; fourth, the tally 
or degree of certainty of the P,REMISE; and last, the certainty factor -- a 
measure of how strong our belief in this conclusion would be, 
assuming bhat 
the PREMISE of the rule is definitely true. 
CONCLUDE 
I------- 
TEMPLATE: 
(CNTXT FARM VALU TALLY CF) 
To illustrate how this is used, consider an explanation that 
involves finding all rules which could cbnclude that the identity of an 
organism is Neisseria. The appropriate swe.cialist would start with those 
rules which the avstem uses to conclude values for the parameter IDENTITY. 
Using templates of the varlous ACTION functions which appear in each of 
these rules, the specialist picks out onLy those (like RULE009) which have 
NEISSERIA in their VALJ slot. 
ThQ also illustrates the sort of knowledqe that can be built into a 
specialist . The specialist knew that the control structure uses stored 
lists telling which rules can be used to determine the value of each 
parameter. Furthermore, ~t knew that lt was necessary to look only at the 
rules' ACTIONS because it 1s the ACTION that concludes facts, while the 
PREMISE uses facts. 
2.2.3 The History Tree 
Many of the explanation capability's specialists need a record of 
the consultation. This record 1s built during the consultation, and is 
organized into a tree structure called the history tree which reflects 
MYCIN'S goal-directed approach. Each node in the tree represents a goal and 
contains Information about how the system tried to accomplish this goal: bv 
asking the user or by trying rules. Associated with each rule is a record 
of whether the rule succeeded, and if not, why it failed. If trying some 
rule causes the system to trace a new parameter, thereby setting up a 
subgoal, the node for this subgoal is the offspring of the node containins 
the rule which caused the tracing. Figure 4 illustrates how part of ii 
history tree miwht look, In this example, R1JLE003 caused tracing of the 
parlameter CATEGORY which is used in the PREYISE of this rule, 
Figure 4. Portion of a History Tree 
[RULEOO~ is shown above, see Figure 5 for RULE003 
and RULE0373 
goal: IRENTITY of ORGMISM-1 
ask: question 7 
rules: RULE009 (failed, clause 1) ... RULE003 (succeeded) ... 
2.2.4 Other Doma in-Independent Knowledge 
i 
MYCIN'S question-answering ability is limited to describing the 
- 
system's actions, and explaining what facts the system knows. Some of the 
specialists for answering questions about the consultation make use of loqic 
J 
goal: GRAM of ORGANISM-1 
ask: question 11 
in arriving at their answers. In particular, to explain why a decision 
goal: CATEGORY of ORGANISM-1 
rules: RULE037 (succeeded) ... 
wasn 't ade, the appropriate specialist uses the logical conclusion that the 
answer consists of ex~laining what prevented the system from using each of 
[no rules] 
the rules that would have made that decision. 
I 
w Y 
goal : HOSPITAL-ACQIJIRED of 
ORGANISM-1 
ask: questlon 15 
[no rules] 
i b 
If deductions or comparisons are needed to answer questions of a 
specific type, then the necessary logic is built into the appropriate 
specialist. There is no general representation of knowledge about logic, 
arithmetic, or set theory that the explanation capability can use to make 
inferences from different facts in its knowledge base. To find out whether 
ORGANISM- I and ORGANISM-2 have the same identity, for example, it is 
necessary for the user to ask separately for the identity of each organism, 
then bo compare the answers to these questions. 
2.3 
Scope of MYC~N'S Explanation Capability 
The ourpose of the explanation system is to enable a user to see how 
MCIN makes decisions, both in general and with reference to a particular 
consultation. To make this facility as useful as possible, we have trled to 
antidpate a11 types of questions whlch a user rnlpht ask, and to make every 
part of the system's khowledge base and reaqoning process accessible through 
clear explanations, 
The entire explanation facility consists of a number of components 
or wspecialistsm each capable of giving a single type of explanation. These 
components are grouped into three sets: one for explaining what the system 
is doing at a given time, one for answering questions about the system's 
static knowledge base, and one for answering quest ions about the dynamic 
knowledge base. The fir& set forms MYCIN 's reasoning-status checker ; the 
second and third together make up the system s general question-answer. 
2.3.1 MYCIN 'a Reasoning-St atus Cheaker 
Whenever MYCIN asks a question, the user is allowed to interrogate 
the status of MYCIN'S reanoninq chain bv asking WHY this piece of 
information is important. As explained in sections 2. 1 and 2.2, the system 
asks a question in order to find out about its curpent goal. Conslder the 
portion of a history tree shown in Figure 4. HOSPITAL-ACQUTRED is one 
subgoal, CATEGORY 13 another at the next level up, atid RULE037 links them, 
The ffreasonff for adkinq whether the infection was hospital-acquired, then, 
is based on an attempt to use this rule to determxne the hi~her subgoal. 
The answer to WHY at this pant is simply a display of the goals and the 
rules linkin8 them. We have given considerable attention to rnakin~ this as 
lucid a display as possible. First, since mwhvrf has several other 
interpretations, and no more extensive natural languase processinq is used 
in this component of MYCIN'S EC, the question is expanded to indicate the 
sense in which it will be answered. The higher goal is then presented, 
followed bv the rule. The clauses in the PREMISE of the rule are divided 
into those already esf.ablished and those yet to be determined. Finally, 
since rules may have multiple conelusions about different clinical 
parameters, the relevant conclusion is presented first and all others 
fbllow. 
As Fiaure 5 illustrates, further sections of the reasoning chain can 
be examined by repeating the WHY command. For any of the subgoals mentioned 
in answer to a WHY, the user may ask HOW this qoal was (or will be) 
achieved. 
MYCIN 's reasoning-status checker is described in more detail in 
[3,4,61 
b 
. [preceded by the first 14 questions in the consultation] 
. 
15) Is the patient's illness with ORGANISM-1 a hospital-acquired infection? 
** WHY 
[i.e. WHY is it important to determine whether or not the infection with 
ORGANISM-1 was acquired while the patient was hospitalized? ] 
f l .Ol 
This will aid in determining the category of ORGANISM-!. 
It ha3 already been established that 
[1.1] the gram stain of ORGANISM-1 is gramneq, and 
[I .2] the morphology of ORGANISM-1 is rod, and 
[1.3] the aerobicity of ORGANISM-1 is facultative 
Therefore, if 
[ 1.41 the ineection with ORGANISM-1 was not acquired while the 
patient was ho,s~ital ized 
then 
there is strongly suggestive evidence ( 8) that the cateaory of 
ORGANISM-1 is enterobacter iaceae 
ALSO: there is weakly dugqeetive evidence (. 1) that the identity of 
ORGANISM-1 is pseudomonas-aeruginosa 1 
[RULE0371 
WHY 
[i.e. WHY is it important to determine the category of ORGANISM-I?] 
[2.0]. . . in brder to determine the identity of ORGANISM-1 
It has already been established that 
C2.11 this blwd culture was taken from a sterile source 
Therefore, if 
[2.2] this current organism and at least one of the list of members 
associated with the category of the orqanism agree with 
respect to the following properties: air conformation 
then 
There is strongly suggestive evidence (.9) that each of them is the 
identity of ORGANISM-1 
[RULE003 1 
** HOW 1.3 
[i.e. HOW was it established that tke aerobicitv of ORGANISM-1 is 
facultative? 1 
The following were used: 
[ 3.1 1 RULE027 ndicat ed the~e is stronqly sugqest ive evidence ( .8 ) that the 
aerobicLty of ORGANISM-1 is facultative 
[ 3.23 RULE027 indicated there is weakly suggestive evidence ( .2) that the 
aerobicity of ORGANISM-1 is anaerobic 
Since this gave a cumulative CF of ('8) for facultative, and (.2) for 
anaerobic, it has been established that the aerobicity of ORGANISM-1 
is facultative 
** HOW 1.1 
[i.e. HOW was it established that the gram stain of ORGANISM-1 is qramneg?] 
You said so [question 1 1 3. 
Figure 5. MPCIN's Reasoning-Status Checker 
[user entries follow the double asterisks] 
2.3.2 MYCIN'a General Question Answerer 
The question-answering part of the systerll has natural-lanqusqe 
routines for analyzinq the user's input. The syatem recoanizes questions 
phrased in a number of ways, thereby makinq the q~est~ion-answering facil-ltv 
easier to use. Questions about the static knowledge base may deal with 
judgmental knowledge (e.g., which rules use or conclude a certain piece of 
information) or they may ask about factual knowledge -- entries in tables 
and lists. Some questions about static knowledge are shown in Figure 6. 
IS BLOOD A STERILE SITE? 
WHAT ARE THE NONSTERILE &SITES? 
WHAT ORGANISMS ARE I IKEL'Y TO BE FOUND IN THE THROAT? 
IS BACTEROIDES AEROBIC? 
WHAT METHODS OF COLLECTING SPUTUM CULTURES DO YOU 
CONSIDER? 
WHAT DOSAGE OF STREPTOMYCIN DO YOU GENERALLY RECOMMEND? 
HOW DO YOU DECIDE THAT AN ORGANISM MIGHT BE STREPTOCOCCUS? 
WHY DO YOU ASK WHETHER 'THE PATIENT HAS A FEVER OF UNKNOWN 
ORIGIN? 
WHAT DRUGS WOULD YOU CONSIDER To TREAT E.COLI? 
HOW DO YOU USE THE SITE OF THE CULTURE TO DECIDE AN 
ORGAN ISM'S IDENTSTY? 
FQure 6. Sample Questions about MYCIN'S Static Knowledge 
Perhaps the more important   art of the question-answering svstem is 
its abllity to answer questions about a  articular consultation. While some 
users may be interested In checklng the extent of MYCIN'S static knowledge, 
most questions will ask for a justification of, or for the rationale behind, 
particular decisf on3 which were made during the consultation. Outlined in 
Flgure 7 are the types of questions about dynamlc knowledqe which can b* 
handled at present. A few examples of each type are given. <Cntxt> 
indicates some context which was discussed in the ~nnsultatlon; <parm> is 
some clinical parameter of this context; <rule> is one of the system's 
decision rules. 
I) 
what is <parm> of <cntxt> 
TO WHAT CLASS DOES ORGANISMm1 BELONG? 
IS ORGANISM-1 CORYNEBACTRRIWM-NOW-DTPHTHERIAE? * 
2) 
how do you know the value of <parm> of <cntxt> 
HOW DO YOU KNOW THAT CULTURE-1 WAS FROM A STERILE 
SOURCE? 
DID YOU CONSIDER THAT ORGANISM-1 MIGHT BE A 
BACTEROIDES? 
WHY DON 'T YOU THINK THAT THE SITE OF CULTURE-1 
IS 
URINE? 
WHY DID YOU RULE OUT STREPTOCOCCUS AS A POSSIBILITY 
FOR ORGANISM-1'1 
3) how did you use <parm> of <cntxt> 
DID YOU CONSIDER THE FACT THAT PATIENT-1 IS A 
COMPROMISED HOST? 
HOW DID YOU USE THE AERORICITY OF ORGANISM-I? 
4) why didn t you find out about <garm> of <cntxt> 
DID YOU FIND OUT ABOUT THE CBC ASSOCIATED WITH 
CULTURE-I? 
WHY DIDN'T YOU NEED TO KNOW WHETflER ORGANISM-1 IS A 
CONTAMINANT? 
5) what did <rule> tell you about <cntxt> 
HOW WAS RULE 178 HELPFUL WHEN YOU WERE CONSIDERING 
ORGANISM-'I ? 
DID RULE 116 TELL YOU ANYTHING ABOUT INFSCTION-I? 
WHY DIDN'T YOU USE RULE 189 FOR ORGANISM-2? 
Figure 7. Sample Questions about a Consultation 
Before a question can be answered, it must be classif$ed a3 
belonginq to one ,of these groups. As Figure 7 illustrates, each question 
type includes a variety of ways in which the question can be worded, some 
specifying the parameter's value, some phrased in the negative, and so 
forth. MYCIN'S natural-language Drocessor must classify the questions, then 
determine what cllnLcal parameters, etc. the question references. 
2,4 Understanding The Question 
The main emphasis in the development of the MYCIV system has been 
the creation of a production system which can provide sound diaqnoatic and 
therapeutic advice in the field of infectious disease. The explanation 
sfatem was included in the system's original desiqn in order to make the 
consultation program's decisions acceptable, justifiable, and instructive. 
Since the question-answerina facility was not the primary focus of the 
research, it is not designed to be a sophisticated natural-lanquage 
understander. Rather, it uses crude techniqyes, relying strongly on the 
very specific vocabulary of the domain, to ll~nderstand~~ whst information is 
being requested. 
The analysis of a question is broken into three phases: the first 
creates a list of terminal or root words; the second determines what type of 
question is beinq asked (see the classification of questions in Section 
2.3); and the last determines what particular parameters, lists, etc. are 
relevant to the question. 
In the first and last steps, the system dictionary is important, 
The dictionary Contains approximately 1400 words that are commonly used in 
the domain of infectious disease. It ificludes all words that are acceptable 
values for a parameter, common synonyms of these words, and words used 
elsewhere by the system in describing the parameter (e.q., when translating 
a rule into English or requesting the value of the parameter). 
2.4.1 
Reducing the Question to Terminal Words 
Each word in the dictionary has a synonym pointer to its terminal 
word 
(terminal words point to themselbes). For the purpose of analyzing the 
question, a non-terminal word is considered to be equivalent to its 
( terminal) aynonym. 
Terminal words may have properties indicating: 
1) that this word is an acceptable value for some 
clinical parameter(s) 
2) that this word always implicates a certain clinical 
parameter, system list, or table (e.g. the word "identitvll 
always implicates the parameter IDENTITY, which means the 
identity of an organism) 
3) that this word might Xmplicate a certain parameter, 
system list, or table (e.3. the word tlpositiven might 
implicate the parameter NUMPOS, which means the number of 
positive cultures in a series) 
4) that this word is part of a phrase which can be 
thought of as a sinqle word (examples of such phrases are 
"transtracheal aspirationw, Ithow longw, and llnot sterilev1. 
Table 1. Properties of' Terminal Words 
The first three properties are actually inverse pointers which are generated 
automatically from properties of -the clinical parameters, Specifically , a 
word receives the "acceptable valuew pointer to a paramster (property (1) 
above) ilp it appears in the parameter's list of acceptable values -- a list 
which is used during the consultation to check the user's response to 3 
request for the parameter's value. Also, each clinical oarameter, list, and 
table has an associated list of key words that are commonly used when 
talking about this parameter, list, or table. These words are divided 
according to hoM sure we can be that a doctor is referring to this 
parameter list, or table when the  articular word is used in a question. 
It is from this list that terminal words nimplicationn pointers (~Papertiea 
2 and 3 in Table 1 ) are generated. 
During the first phase of parsing, each word in the original text is 
replaced by its terminal word. For words not found in the dictionary, the 
system uses Winograd's root-extraction aleorithm 181 to see if the word's 
lexical root is in the dictionary (ems., the root of tfdecisionw is 
"deciden). If so, the word is replaced by the terminal word for its root. 
Words st111 unrewgnized aFter root extraction are left unchanqed. 
The resulting list of terminal and unrecognized words is then passed 
to a function which recognizes phrases. Usinq propertv 4 (see Table 1) of 
the terminal words in this list, the function identifies a phrase and 
replaces it with a single synonymous terminal word (whose dictionary 
properties may be important in determining the meaning of the question). 
2.4.2 Classifying the Question 
The next step is to classify the question so that the proqram can 
tell which specialist should answer it. Since all auestions about the 
consultation must be about some specific context, the system requires that 
the name of the context (e.g., ORGANISM-1) be stated explicitly. This ~ives 
an easy way to separate qeneral questions about the knowledqe base from 
questions about a particular consultation. Further classification is done 
through a pattern matchinp; approach siailar to that used by Colby [I 1. 
The list of words created by the first phase is tested against a 
number of patterns (about 50 at present). Each pattern has a list of 
actions to be taken if the pattern is matched. These actions set flags 
which indicate what type of question was aaked. In the case of questions 
about judqental knowledge (called rule-retrieval questions), pattern 
matching also divides the question into the part referring to the rule's 
PREMISE and the part referring to its ACTION. For example, in "How do you 
decide that an organism is streptococcus?~, there is no PREMISE part, and 
the ACTION part is "an organism is streptococcus~; in "Do you ever use the 
site of the culture to determine an organism's identity?", the PREMISE part 
is "the site of the culturew and the ACTION part is "an organism's 
identityn. 
2.4.3 Determining What Pieces of Knowledge are Relevant 
The classification of a question guides its further analysis, Each 
question type has an associated template with blanks to be filled in from 
the question, The different blanks and the techniques for filling them in 
are listed in Table 2. With the question correctly classified, the general 
question-ans*erer can tell which soecialist should answer it. Fillin5 in 
all blanks in the template gives the s~ecialist all the information needed 
to find the answer, 
1) <cntxt> - The context must be mentioned by name. 
2) <rule> - Either a rule's name (RULE047) will be 
mentioned, or the word "rulen will appear, toqether wiLh the 
rule 'a number ( 47). 
3) <value> - One of the terminal words in the question 
has a diationary property indicating that it is a legal 
value for the parameter (property 1, Table 1 -- e ,q. THRDAT 
is a legal value for the parameter SITE). 
4) <parm> - All of the words in the list are examined 
to see if they implicate any clinical parameters, Strong 
implicatians come from words with properties showinrf that 
the word is an acceptable value of the parameter, or that 
the word always implicates that parameter (properties 1 and 
2, Table 1). Weak implications come from words with 
nroperties showing that: they might implicate the parameter 
(property 3, Table 1). The system uses an empirical scoring 
mechanism for picking out only the most likely parameters. 
Associated with certain parameters are words or 
patterns which must appear in the question in order for the 
parameter to be implicated. This scheme allows the system to 
distinguish related parameters which may be implicated by 
the same key words in the first pass. For example, the word 
nPMNvf implicates parameters CSFPOLY (the percent of PMNs in 
the CSF) and PMN (the percent of PMNs in the complete blood 
count). These are distinguished by reauirinq that the word 
"CSFn be present in a question in order for CSFPOLY to be 
implic.at ed . 
5 <list> - System lists are indicated in a manner 
slmilar to parameters, except that scoring is not done. 
Lists, like parameters, ,may have associated patterns which 
must be present in the question. Furthermore, lists h~ve 
properties telling which other system lists are their 
subsets. If a question implicates both a list and a subset 
of that list, the more general (larger) list is discarded. 
As an example, the question "Which drugs are 
aminoglyco~ides?~~ implicates two lists: The list of all 
drugs and the list of drugs which are aminoglycosides. The 
system only considers the more specific list of 
aminoglycosides when answering the question. 
6) <table> - Tables are indicated in a manner similar 
to lists except that an entry in the table must also be 
  resent in the question. For exam~le, the word norganismw 
may indicate two tables: one containing a classification of 
organisms, and the other containing normal flora of various 
portals. The question "What organisms are considered to b'e 
subtypes of Pseudornona~?~' will correctlv implicate the 
former table, and "What are the organisms likely to be found 
in the throat?ft will implicate the latter, because 
FSEUDOMONAS is in the first table and THROAT is in the 
second. 
Table 2. Mechanisms for Analyzing a Question 
** WHEN DO YOU DECIDE THAT AN ORGANISM IS A CONTAMINANT? 
[I j Terminal words: WHEN DO YOU CONCLUDE THAT A ORGANISM 
IS A CONTAMINANT 
[23 Question type: Rule retrieval 
Premise p~rt: (WEN DO YOU CONCLUDE) 
Action part: (THAT A ORGANISM IS A CONTAMINANT) 
[3] vocab, clues: (WHENINFECT (ANY) 1) (WHENSTOP (ANY) 1) 
( Premise ) (WHENSTART (ANY) 1 (DURATION (ANY) 1) 
vocab. clues: (CONTAMINANT (ANY) 4) (FORM (ANY) 1) 
/, Act ion ) (SAMEBUG (ANY) 1) (COVERFOR (ANY) 1) 
14 3 Final translation : 
Preaise: ANY 
Act ion : ( CONTAMINANT ANY ) 
151 The rules listed below conclude about: 
whether the organism is a contaminant 
6, 31, 351, 39, 41, 42, 44, 347, 49, 106 
kich do you wish to see? 
** 6 
--ow--- 
If: 1) The culture was taken from a sterile source, and 
2) It is definite that the identity of the organism 
is one of: staphy7~coccus-coag-neg bacillus- 
subt ilis corynebacter ium-non-diphtheriae 
Then: There is stronqly suqqestive evidence ( .8) 
that the orqaniqm is a contaminant 
Figure 8. Sample of MYCIN'S Analysis of a Question 
[User input follows the double asterisks. 1 
[ 1 1 The quest ion is reduced to a list of terminal words. 
C21 Pattern matchinq classifies the question as a rule-retrieval 
question, and divides it into a premise part and an aetfon 
part 
[3] Dictionary oroperties of the temnfna1 words are used to 
determine which parameters (and their values) are relevant 
to each part of the question. These vocabulary clues are 
listed in the form (<parm> (<values>) weight) where weight is 
used by the scoring mechanism to determin which parameters 
should be eliminated from consideration, 
[ 41 After selecting only the most strongly indicated parameters, 
the final translation tells what rules can answer the 
question: there are no restrictions on the PREMISE, and the 
ACTION must contain the parameter CONTAMINANT (with any 
value). 
[5] The answer con8fsts of findinp; all rules which meet these 
restrictions, and printing those that the user wants to see. 
2.5 Answering the Question 
Corresponding to each question type, there are a number of' possible 
answer templates. For example, for questions of the fom ttHow do you know 
the value of <parm> of <cntxt>?", two of the answer templates are: 
I used <rule> to conclude that <parm> of <cntxt> is <value>, 
This gave a cumulative c.f. of (certainty factor), 
The last question asked before the conclusion was made 
was (question number>. 
In answer to question (question number) you said that <parm> of 
<cntxt> is <value> 
The specialist for answering ,questions of a given tvpe will need to check 
the history tree or the system s knowledge base in order to determine which 
of the answer templates is appropriate for a particular question, Some 
blanks in the answer template will be filled in by the same items that 
filled blanks in the question tern~late. The remainder are filled by the 
specialist with information which will answer the question. In the above 
example, the slots <parrn>, <cntxt>, and possiblv <value> would be filled in 
from the question, and the other slots would be fllled from the historv 
tree. 
2.5.1 Questions about MYCIN'S Static Knowledge 
General questions about MYCIN's factual knowledqe are the easiest to 
answer. The specialist that provides answers to such questions must look up 
the desired information in the system's static knowledge base. Generally, 
an answer consists of simply displaying this information. As Figure 9 
illustrates, the most processing that is ever done is to check the retrieved 
information against some item in the question (for eauality of set 
membership). 
** IS BLOOD A STERILE SITE? 
Yes. Blood is one of those sites that are normally sterile. 
** WHAT ARE THE NONSTERLLE SITES? 
Those sites that are normally nonsterile are: CERVIX, 
CUTANEOUS-ULCER, LOCHIA, NOSE, SKIN, STOOL, THROAT, URETHRA, 
VAGINA, 
** WHAT ORGANISMS ARE LIKELY TO BE FOUND IN THE THROAT? 
The 1 ikely  ath hog ens associated with throat are : STREPT0C)OCCUS- 
PNEUMONIAE, STREPTOCOCCUS-GROUP-A, NFISSERIA-YGYINGITIDIS. 
** IS BACTEROIDES AEROBIC? 
No, the aerobicity of bacteroides is anaerobic. 
* * WHAT DOSAGE OF STREPTOMYCIN DO YOU GENERALLY RECOMMEND? 
The suggested dosage and route of streptomycin is 7,5 ma/kq 
q12h IM (or IV). 
** ROW DO YOU TREAT MENINGOCOCCAL BACTEREMIA? 
For treatment of NEISSERIA-MENINGITIDIS in PRIMARY-BACTEREMIA 
Select therapy from among the following drugs (ranked according 
lo relative efficacy, assuming uniform sensitivity) : 
PENICILLIN (091 
AMPICILLIN ( -9) dose: 30 mg/kg q6h 
SULFISOXAZOLE ( -8) dose: 60 rnq/kg IV then 15 ms/kg q4h IV 
for 48 days then 15 mq/kq q4h PO 
CHLORAMPHENICOL (.7) 
ERYTHROMYCIN (.5) 
TETRACYCLINE (84) 
Duration of therapy: 14 days 
Figure 9. Questiorrs about Factual Knowledge 
The specialist thzt answers questions about j~dqUIenta1 knowledge is 
slightly !nore complicated. Answering these questions (Flqure 10) involves 
built-in knowledge about the rule set, plus the ability to tlreadll the rules. 
By the time the question has been analyzed, the mecialist knows exactly 
which parameters must appear in the PREMISE, and which must apDear in the 
ACTION of any rule which answers the question. 
Values may be specified for 
any of the parameters. To answer the question, the rule-retrieval specialist 
must first find every rule whose PREMISE and ACTION satisfy these 
constraints. To do this, it needs to know that there are two special lists 
associated with each parameter: one contain in^ every rule that uses the 
parameter in its PREMISE, and the other containinq every rule that concludes 
about the parameter in its ACTION. Using these lists for the various 
parameters mentioned in the quest ion, the specialist can find those rules 
that might answer the question. If no values were soecified, the job is 
done and the relevant rules can be displayed without further anslvsis; 
otherwise, it is necessary to read each of the rules in the list and to 
eliminate those which do not mention the correct values for the ~arameter, 
The rule-retrieval specialist also makes use of a piece of MYCIN'S 
knowledge which was not discussed earlier. The system contains models of 
its own knowledge (called rule models) which are used primarily during 
acquisition of new medical knowledge from an expert [4]. These models, 
however, can be put to many uses -- one is to explain aeneral patterns in 
decision making. The rule models are abstract descriptions of a subsets of 
rules and are generated automatically by readinq the rules. For examole, 
the model for IDENT-IS-PSEUDOMONAS tells what features are common to the 
majority of rules which conclude that the identity of an oraanism is 
pseudomonas . 
If a model exists describing the rules about which the question is 
asking, the rule-retrieval soecialist incorporates this model's information 
into its answer (Figure 11). Thus the question-answering facility is able 
to give some information about strategies for achieving some of the svstem's 
goals, as well as the individual rules which use the strateqies. 
** WHY DO YOU ASK WHETHER THE PATIENT HAS A FEVFR OF UNKNOWN 
ORIGIN? 
The rules listed below use: 
whether the patient has a true fever of unknown ori~in 
RuLE180 
n.l-.1--- 
If: 1 ) The site of the culture is blood and 
2J The number of cultures in the series including the 
culture is qreater than or equal to 1, and 
3) The number of culturea in this series which were 
positive for the orqanism is less than or equal to 1, 
and 
4) The patient has a true fever of unknown origin, and 
5) "ardiac-surgery is a relevant item from the history of 
the patient 
Then: There is suggestive evidence ( '6) that the infection is 
infective-endocardit is 
** WHAT DOES GIJ MANIPULATION TELL YOU ABOUT THE IDENTITY OF AN 
ORGANISM? 
The rules listed below use: 
whether the patient has had a senito-urinary manipulative 
procedure 
to conclude about: 
the identity of the organism 
156, 163, 190 
Wfiich do you wish to see? 
** 156 
RULE1 56 
mwm3(--- 
If: 1) The site of the culture is blood, and 
2) The gram stain of the organism is gramneq, and 
3) The morphology of the orqanism is rod, and 
4) The portal of entry of the organism is urine, and 
5) The patient has not had a qenito-urinary manipulative 
procedure, and 
6) Cystitis is not a problem for which the patient has 
been treatel? 
Then: There is suggestive evidence (.6) that the identity of 
the orqanism 1s e. coLi 
Figure 10. -Rule-Retrieval Questions 
** HOW DO YOU DECIDE THAT AN ORGANISM MIGHT BE 
PSEUDOMONAS AERUGINOSAQ 
Rules which conclude that the identity of the organism is 
pseudomonas-aeruginosa generally use one or more of the 
following pieaes of information: 
the sfte of the culture 
the Gram stain of the organism 
the morphology of the oreanism 
Furthermore, the following relationships hold: 
The gram stain of the orsanism, and the morphology of the 
organism tend to appedr together in these rules. 
RULE184, RULE1 16, RULE047, RULE085, RULE040 conclude that 
the identity of the organism is pseudomonas-aeruqinosa. 
Which of these do you wish to see? 
** 184 
RULE1 84 
If: 1 ) The category of the organism is not known, and 
2) The aram stain of the orsanism is qrarnneg, and 
3) The morphology of the organism is rod, and 
4) The aerobicity of the organism is facul 
Then: There is weakly sugqestlve evidence (.I) that the 
identity of the orqanism is pseudomonas-aeruqinosa 
Figure 1 1. Question Which Uses Rule Models 
2.5.2 Consultation-Specific Questions 
One of the simplest quest ions about a spec if ic consultation inquires 
about the value of a particular parameter (Figure 12). The specialist which 
answers these questions must know how to retrieve this information, In soae 
cases it will also be necessary to make comparrsons to see whether a value 
specified in the auestion is one of the values which was deduced for that 
parameter. 
** TO WHAT CLASS DOES ORGANISM-1 BELONG? 
The category of ORGANISM-1 is enterobacteriaceae ( '9) 
#* IS ORGANISM-1 A STREPTOCOCCUS? 
No. 
The identitv of ORGANISM-1 is e.coli 1.74) bacteroides (.7) 
klebaiella-pneumoniae (.4) ~seudomonas-aeruginosa (.22) 
enterobacter (.21) proteus-non-mirabilis (.19) serratia (.O3) 
salmonella (.02) 
Flgure 12. Questions about a parameter's Value 
Answerinq other tllrpes of consultation-specific questions involves 
the use of knowledge about the control strbcture, including: 
1) 
how the system acquires information 
2) why the system tries to find out about parameters 
3) how information is used once it is acquired 
4) what causes a rule to be tried 
5) what causes a rule to fail, 
The specialist for answering questions like !!How do vou know the 
value of <parm> of <cntxt>?w, knows that the value of a narameter can come 
from two sources: it can be deduced by rules, or the user can tell us about 
it in response to a question. The history tree (see Section 2.2) will show 
whlch (possibly both) of these sources provided the particular informatton 
mentioned in the question (Figure 13). 
** HOW DO YOU KNOW THAT CULTURE-1 WAS FROM A STERILE SOURCE? 
I used rule189 to conclude that this blood culture was taken from 
a sterile source. This gave a cumulative c.f. of (1.0). The 
last question asked before the conclusion was made was 7, 
** DID YOU CONSIDER BACTEROIDES AS A POSSIBILITY FOR ORGANISM-I? 
Yes. I used rule095 to conclude that the identity of ORGANISM-1 
is bacteroides. This gave a curdulative c.f. of (,7). The 
last question asked before the conclusion was made was 20. 
** HOW DO YOU KNOW THAT ORGANISM-1 IS E.COLI? 
The following rules made conclusions about whether the identity 
of ORGANISM-1 is e.coli 
cumulative certaimy last quest ion asked 
RULE Yes No before conclusion was made 
RULE021 
(447) 20 
RULE0 84 
(455) 22 
MI LEO 03 
(a741 24 
In answer to question 9 you said that the identity of ORGANISM-1 
is e,coli (,3) 
Figure 13. Question Regarding How a Conclusion Was Made 
If the question is phrased in the negative, it is neeessarv first to 
find all the ways the conclusion could have been made (this is a simple task 
of rule-retrieval), then to explain why it wasn't made in this consuLtation 
(Figure 14). The mecialist for answerinq these questions must know what 
situations can prevent conclusions from beinq made. The second question i~ 
Figure 14 illustrates how the answer+ to one question aisht cause another 
question to be asked. 
** WHY DID YOU RULE OUT STREPTOCOCCUS AS A POSSIBILITY FOR 
ORGANISM-I ? 
The following rules could have b?en used to determine that the 
identity of ORGANISM4 is streptococcus : RULEO33. However, 
none of these succeeded in the context of ORGANISM-1. 
If you would like an explanation for why any of these 
rules failed, please enter their numbers: 
*# 33 
Clause 2 of rule033 ["the morpholoqy of the orqanasm is coccusw] 
was already known to be false for ORGANISM-1, so the rule 
was never tried. 
** WHY DON 'T YOU THINK THAT THE MORPHOLOGY OF ORGANISM-1 IS 
COCCUS? 
It is definite that the morphology of ORGAVISY-1 is rod. Knowing 
this with certainty rules out all other values for the 
the morphology of 0RQ.ANISM-1, includinq coccus. 
Figure 14. Questions Regarding Why a Conclusion wasn't Made 
The specialist for answerinq questions of the fom "How did vou use 
<parm> of <cntxt>?IV, needs to know not only how to find the svecific rules 
which might use a parameter, but also how a ~arameter can cause a rule to 
fail 2nd how one parameter can prevent another from being used. The history 
tree can be checked to see which of the relevant rules used the oarameter, 
which failed because of the parameter, and which failed for some other 
reason, preventin@ the parameter from being used (Figure 15). 
** HOW DID YOU USE THE AEROBICITY OF ORGANISM-17 
The aerobicity of ORGANISM-1 was used in the following rules: 
RULE003, RULE005, RULE084. 
The aembicity of ORGANISM-1 caused the following rules to fail: 
RULEO35, RULEO51, RULE052, RULEO'i3, RULE111c 
Thc aerobicity of ORGANISM-1 also would have been used in: 
RULE037, RULEOSO. RULE058, RULE086, RULE110, RULE184, 
RULE203, RULE204, RULE205. However, none of these 
succeeded In the context of ORGANISM-1. If you would 
like an explanation For why any of these rules failed, 
please enter their numbers: 
** 37 
Rule037 was tried in the context of ORGANISM-1, but it failed 
due to clause 1 ["the categorv of the organism is not 
known"] . 
** DID YOU CONSIDER THE FACT THAT PATIENT-1 IS NOT A COMPROMISED 
HOST? 
The fact that Fred Jones is not a compromised host caused the 
following rules to fail: RULE085, RULE106. 
The fact that ~rea Jones is not a compromised host also would 
have been, used in: RULE109. Howeveri none of these 
succeeded in the context of PATIENT-1.. If you would 
like an explanation for why any of these rules failed, 
* 
please enter their numbeps: 
** NONE: 
Figure 15; Queathns Regarding How Information Was Used 
For questions of the form "Whv dldn't you find out about <parin> of 
<cntxt>?.", qeneral knowledge of MYCIN'S control structure tells the 
conditions under which it would have heen necessary to find out some piece 
of information. The record of the consultation can be used to determine why 
these cohditions never arose for the particular parameter in question 
(Figure 16)-. 
Figuae 16 also illustrates that MYCIN'S GQA allows a user to 
get as 
much information as is desired. The first answer given was not really 
complete In itself, but it led the user to ask another question to yet more 
information. Then another questlgn was asked to determine why clause 1 or 
RULEI~~ was false. The answers to the first two questions both mentioned 
rules which could be printed if the user wanted to examine them. The 
special command PR (Print ~ule) ig for the user's convenience. It requires 
no natural-languaqe processing and thus can be understood and answered 
immediately. (What is rule or *'Print rule 109 ." also would have been 
underst oad . ) 
** DID X8U FIND OUT A6OUT THE CBC ASSOCIATED WITH CULTURE-I? 
During t be preceding consultation, I never had reason to try to find out 
whether the results of the CBC from the time period of this blood 
culture are available. It would have been necessary to know this 
information in order to use any of the following: RULE109. However, 
none of these succeeded in the context of this blood culture. If you 
would like an explanation for why any of these rules failed, please 
enter their numbers: 
** 109 
Rule109 would be relevant to this blood culture when ap~lied to: ORGANISM-1. 
I never had reason to trv to apply rule109 to ORGANISM-1. I would have 
needed to use rule109 in order to find out whether ORGANISM-1 is a 
contabinant. However, during the preceding consultation, 1 never had 
reason to trv to find out whether ORGANISM-1 is a contaminant. 
** WHY DIDN'T YOU NEED TO KNOW WHETHER ORGANISM-1 IS A COWTAMINANT? 
During the preceding ~onaultation, 1 never had reason to try to find out 
whether ORGANISM-1 is a contaminant. It would have been necessarv to 
know this information in order to use any of the followinq: RULEOO6, 
RULE007, RULE906, RULEt08, RULE109, RULl3159. However, none of these 
succeed'ed in the context of ORGANISM-1. If you would like an 
explanation for why any of these rules failed, please enter their 
numbers: 
** 159 
Rule159 was tried in the context of ORGANISM-1, but it failed due to clause 
1 ["it is suspected that the identity of the organism is 
corynebacterium-non-diphtheriaew 1 
** IS ORGANISM-1 CORYNEBACTERI UM-NOW-DIPHTRERIAE? 
No. The idedtity of ORGANISM-1 is e,coli (.74) bacteroides (.7) 
klebsiella-pneumoniae (.4) pseudomonas-aeruqinosa (22) enterobacter 
(.21) proteus-non-mirabilis (.I91 serratia (.03) salmonella f.02) 
** PR 109 
RULE 109 
If: 1) The cuJture was taken from a sterile source, and 
2) Xt is not known whether tb e orqanism is a contaminant, and 
3) The patient is not 9 compromised host, and 
4) The patient was febrila due to the infection, and 
5) The results of the cbc from the time ~eriod of the culture are 
available, and 
6) A - The white count from the CBC is qreater than 10.5, or 
B - The percent of pmn's in the cbc at the time the culture was 
obtained is qreater than 78, or 
C - The percent of wbc's which were bands in the CBC at the 
time the, culture was obtained is qreater than 10 
Then: There is strongly suggestive evidence (.a) that the orqanism is 
not a contaminant 
Figure 16. Questions Regarding Why a Parameter wasn't Traced 
In questicns asking about the application of a rule to a context 
there are three poss*~bilities: the rule told us somethinq about the context; 
the rule failed when applier! to that context; or the rule was never tried in 
that context, The historv tree tells which of these ia the case, 
Furthermore, if a rule succeeded, there is a record of all the conclusions 
it made, and if it I"3ileb, the reason for failure is recorded. 9s Fiqure 17 
illugtrates, rules are only applicable in certain contexts. If the rule 
could not apply to the context mentioned in the question, but mi~ht be 
relevant when applied to soae other context [which is an ancestor or 
descendent in the context tree], then the question is answered as if it had 
mentioned the relevant context. 
There are interactions among the different types of questions which 
weren't mentioned earlier for the sake of clarity. Sometiaes a question ray 
indicate an incorrect assumption about the sate of MYCIN'S knowledge. For 
examole a question could ask "Whv don't you think that ORGANISM-1 is 
E.coli?" when, in fact, the system has concluded that the organism is 
E.coli. To answer this question, the explanation system would explain how it 
did make such a decision, despite the ~hrasinq of the question. Similarlv, 
when asked how the system used (or concluded about) some mrameter that was 
never traced, the system explains why it didn 't need to find out about the 
parameter, reflardless of how the question was bhrased. 
** DID RULE 116 TELL YOU ANYTHING ABOUT INFECTION-I? 
~ulell6 would be relevant to the primary-bacteremia when applied 
t: ORGANISM-1 
Clause 5 of rulel 16 ["the infection is meninqitisn] was already 
known to be false for ORGANISM-I, so the rule was never tried. 
** HOW WAS RULE. 178 HELPFUL WHEN YOU WERE CONSIDERING ORGANISM-13 
~ule178 would be relevant to ORGARISM-1 when applied to: 
CULTURE-I 
I never had reason to try to apply rule178 to this blood culture. 
X would have needed to use rule178 in order to find out 
whether this blood culture was taken from a sterile source. 
However, I was already certain that this blood culture was 
t&ken from a qterile source, 
** WHAT DID RULE 295 TELL YOU ABOUT ORGANISM-I? 
I used rule295 to conclude that the identity of ORGANISM-1 $3 
hemophilus-influenzae. This gave a cumulative c.f. of (25). 
The last question asked before the conclusion was made 
was 36. 
+* WHY DIDN'T YOU USE.RULE112 TO FIND OUT ABOUT ORGANISM-I? 
RULE1 12 was not executed because it would have caused circular 
reasoning when applied to ORGANISM-?. Would you like ta 
see the chain of rules and parameters which makes up this 
circle? 
** YES 
1 wanted to know about the identity of ORGANISM-1 -because I 
try to find out the identitv of the organism for all 
current organisms of the patient. 
To find out about the identlty of ORGANISM-1, I tried to use 
ruleO21. Before I could use rule021, I needed to know about 
a prior orqanism with possibly the same identity as 
ORGANISM-1 . 
To find out about a prior organism with possibly the same 
identity as ORGANISM-1, I trred to use rule005. Before I 
could use rule005, I needed to know about the aerobicity of 
ORGANISM-1 . 
To firid out about the aerobicity of ORGANISM-1, I tried to use 
rule031. Before I could use rule031, I needed to know about 
the category of ORGANISM-1. 
To find out about the category of ORGANISM-1, I tried to use 
rulel 12. Before I could use rulel 12, I needed to know about 
the identity of ORGANISM-1 . 
But this is the unknown parameter I sought originally. 
Figme 17. Question Regarding the Application of a Rule 
3 Conclusions 
Consultation system8 which give expert advice in some domain form 
one class of artificial intelligence programs which can provide useful 
solutions to real-world ppoblems. The utility of such a system, however, 
depends on its acceptability to human users. One feature which can Increase 
a system's acceptability is a mechanism whereby the system can explain or 
justify its advice. 
The development bf an explanation mechanism for a consultation 
system is very much related to the problems of representing knowledge and of 
making use of different sources of knowledge, Since the production system 
formalism provides a unified way to represent modular pieces of knowledae, 
the task of designing an explanation capabilitv is simplified for 
production-based consultation systems, The example of MYCIN shows how this 
can be done and illustrates further that a svsterll desiqned for a single 
domain with a small, technical vocabulary can give comprehensive answers to 
a wide range of quegtions without sophisticated natural-language processing. 
Acknowledgments 
The authors wish to express their qratitude for the inbrest and 
advice of Drs. Bruce Buohanan and Cordell Green (Computer Science 
Department). We also are indebted to the followinpr MYCIN Project co- 
workers: Jan Aikina, Stanton Axline, Stanley Cohen, Larry Fagan, Frank 
Rhame, Bill van Melle, Sharon Wraith, and Victor Yu. Special thanks are due 
to Bill van Melle and Bruce Buchanan who made numerous helpful comments on 
earlier drafts of the paper. 
Ph~l~p S, Nyborg, Director 
Wash~ngton Offlce 
d% Washington Report 
t**********C****************************** 
Amer~can Federabon of lnforrna on Processing Soaebes, Inc 
Su~te 420 2100 L Street, N W , Wash~ngton, D C 20037 
202-296-0590 
Vol. 11, No. 10 
November, 1976 
NASHINGTON DEVELOPMENTS 
SUPREME COURT DENIES CBCT PETSTIONS; COMPTROLLER CURRENCY TO ISSUE NEW CBCT 
&GULATIONS 
Consolidated petitions from two Chicago banks and the Comptroller of the 
Currency seeking review of Pedeyal Appeals Court rulings which equate 
customer-bank conlmunications terminals (CBCTs) with bank branches, and thus 
forbid CBCTs in nonbranching states, were denied by the Supreme Court last 
month ttwithout dissent or explanation ." 
Banks ' response. The petitioning banks, Gontinental Natiofial Brink and Trust 
Co. of Chicago and the First National Bank of Chicago, this month deactivated 
their combined total of seven CBCTs . The terminals' three uses permit 
deposits to be made, funds to be transferred, or funds to be borrowed; each 
of the5e functions, various appea-1s courts have held, constitute branch bank- 
ing under the National Bank IMcFadden) Act. 
New CBCT regutatiom. The Currency Comptrollerts Attorney Edward Jiran told 
AFIPS P~ehington Report in October that the Comptroller will issue new regu- 
lations for nat%onal bank CBCTs this month. 
Rules may be written to liberalize minimum capitalization requirements for 
terminals shared by more than one financial institution, according to the 
Comptroller s Electronic Banking Systems Division Chief Claude A. Raworth. 
Pawortb told AFIPS that the new regulations will permit banks Itto use the 
[EFTS] technology without heavy capitalization requirements; [otherwise, 1. 
some thinly capitalized [banks] would have problems ." Thus, according to the 
Currency Comptroller official , the regulations would encourage sharing EFTS 
facilities with smaller banks. 
NCEFT'and ZegisZatim acti~ties. Prior to the Supreme Court action denying 
the CBCT petitions, National Commission on Electronic Funds Transfer (NCEFJ') 
Executive Director John B. Benton told this writer in Washington that the 
braaching issue should be resolved in the U.S. Congress, Benton added that 
"it's going to be some time before 1egi.slation is passed in CongressIt on 
whether CBCPs are branches. 
Last month, the NCEFT convened hqar~ngs osl both brahching and corlsumer issues. 
The Senate Subcommittee on Financial ~hsstitutions, chaired by Sen. Thomas dr 
McIntyre ID-N .H .) , wi 11 hold hearings on the branching question in December. 
CBCT court action. Fedgral courts in various jurisdictions have bean almost 
unanimous in their interpretation of the McFad&n Act disallowing off-premises 
CBCTs. Last August, the U.S. Court of Appeals for the Tenth Circuit, ruling 
in a Colorado case, upheld a lower district court judgment that receipt of 
deposits by CBCTs vialates the McFadden Act. 
The U. S. Court of Appeals for the Eighth Circuit, in a separate case, last 
July upheld a district court ruling in Missouri that the First National Bank 
in St. Louis must remove CBCTs at two St. Louis County locations. The district 
court said that any one of the three major services provided by CBCTs consti- 
tuted branch banking, which is limited in Missouri. 
In the cases of the two petitioning Chicago banks, decided by the Federal Court 
of Appeals in Illinois last May, all functions performed by CBCTs were deemed 
to constitute branch banking, which is forbidden in 11,Jinoi.s. 
However, a Federal District Court in Oklahoma approved all three uses of CBCTs, 
finding terminals "only processors ,Iv and as such legal. An appeal of the case 
was mooted when the. state legislature authorized legislation aaactioning the 
use of CBCTs. 
GOVERNhIENT OPERATIONS COMMITTliE CRITICIZESNONCOMPETITIVljG PROCUREMENTS 
Following hekrings last June (Washinqton Re~mt, 8/76), the House Cornittee on 
Government Operations stated in October that "the low level of fully competitive 
ADP promrements, coupled with the apparent lack of effective utilization of 
ADP resources will, if allowed to continue, ultimately result in seriously 
jeopardizing the effectiveness of the Brooks Act [P.L. 89-3061, at a cost of 
millions of dollars annually to the taxpayers." 
Reexam.inution of 'true -ct of computere ' suggee.ted. In a report, titled 
Administration of P. L. 89-306, Procwernnt of ADP Re8omes By ths FedemZ 
Covement (II,), the Committee said: "If'the full benefits of the'Act are to be 
achieved, GSA, OMB, NBS, and the user agencies must join together in a commit- 
ment tb fully support and adhere to the provisions of the Act." 
The report suggested a reexamination sf "the true impact of computers on govern- 
ment operations." It raised the question of whether "acquisition of ADP 
resources is necessary to carry on an essential program, or whether such 
acquisition will foster non-essential activity because the computer is available." 
ADP ~t. . . receive attenth of top management. The Committee concluded 
that ADP Itcam no longer be viewed as a mere tool, but must now be treated in the 
same way as other major programs and, as such, receive top attention of top 
management." The report attributed the basic causes of noncompetitive procure- 
ments to a lack of: (1) adequate justifications for ADP acquisition; (2) 
long-range planning; (3) standards ; (4) high level languages ; (5) utilization 
~euiews; and (6) use of functional specifications. 
OMB directs GSA to use vfbwtiomZ ADP specifiwtions*. 
Responding directly to 
the Committee report and other criticisms, OMB Dlrector James T. L 
letter last month to GSA Administrator Jack ECkerd, wrote that "[t $a o preclude in a 
the adverse effects of unduly restrictive specifications, agsncies shall, to 
the maximum practical exrent, express their ADP requirements in terms of 
functional performance specifications rather than equipment specifications . " 
Lynn added: 
"GSA should strive for expeditious review of agency submission 
to avoid delays in the procurement process. 
Agencies should cooperate with 
GSA to expedite these reviews. An undue length of time for the normal ADP 
procurement process may be considered a disagreement by GSA with the request 
of the agency, and may be appealed to the Office of Management and Budget. 
fvConsistent with the poliw expressed herein, any such appeal will be handled 
expeditiously, but the burden will be upon the agency to demonstrate the need 
to specify the particular make or model of equipment or its functional 
equivalent when such specification is at issue," he said. 
The GSA has 60 
days fi- October 6, the date of thb letter, to comply with the directive. 
HOUSE COMMUNICATIONS SUBCOWITTGE CHAIRMAN RECOMMENDS OVERHAUL OF 1934 
COM~UNICATIONS ACT 
A "basement - to-at t icl' overhaul of the 1834 Federa2 Commmications Act, the 
statute which provides the basis for regulation of the nation's telecomuni- 
cations systems, was proposed to the next Congress last month by Rep. Lionel 
Va Deerlin (D-Calif.), chairman of the House Communications Subcommittee. 
The Submcomittee has just completed three day* of hearings on the proposed 
Cone~wr Comnications Refon Act of 19F6 (Waehh-gton Report, lo/ 76) . 
Joined by Rep. Lou Erey.@-Fla.), Van Deerlin said the original Act is out- 
dated. 
According to the trade press, issues to be considered by the Subcommittee 
include : whether the FCC has established fair coppetiti:~.: ground rules; 
whether business telephone services really subsidize residential services; 
and what the implications of changing FCC policies are toward competition. 
NEW TAX ACT REPEALS PART OF 1974 PRIVACY ACT ON STATE USE OF SOCIAL SECURITY 
MIEriBER 
President Ford last month signed into law the Tm Reform Act of 1076, recently 
passed by Congress (va~hinqtofl Repopt, 9/ 76 ) , which includes an amendment 
pemktting state governments to demand and retain an individual's Social 
Security Number [SSN) to aid in searches for parents not supporting their 
children. The amendment repeals part of the Acivacy Act of 1974. 
In addition, state and local governments can now use the SSN as an identifier 
for tax administrative programs, for drivers ' licenses, and for motor vehicle 
registration. However, government officials who disclose the nmber without 
authorization are subject to a fine o!f up to $1,000 or imprisonment of up to 
one year. 
NEWS BRIEFS 
Rep. TiarWirth [D-Colo.) last month wrote Office of Teleconmnmications Policy 
ETP) Director ,momas Houser (who had reportedly c~ntacte~ Assistant 
Attorney General Donald Baker to discuss the "economic rationale" for 
the Governmpnt ' s antitrust action against ATBT) tliat Itany further contacts 
between OTP and the Departwent of Justice, concerning the [suit]. . . 
would be most iaappropriat e . 
The - FCC last month set new dates for providing comments on the second "Computer 
InquiryH and rulemaking regarding the use of computers by common carriers 
jn -providing communciations or data processing services ; comments are now 
due by January 10, 1977; replies, by February 24, 1977. 
Responding to protests by -9 AT&T the - FCC last month revised registration 
specifications for modems to facilitate direct interconnection of modems 
to the telephone network. 
The House Government Operations Committee last month failed to report to the 
House floor a bill that would have authorized the Federal Assistance 
Program Retrieval System (FAPRS)'. 
The Institute for Cowuter Sciences - and Technology - [ICST) of the National 
Bureau of Standards QBS) last month issued DisR Drive Interface Charm- 
teAetics (# --enclose $5.50) ; the report was prepared by Auerbach 
Associates under NBS contract, and deals with charact-eristics of the 
interfaces between high performance disk drives and their controllers. 
The National Communi-cations System (NCS) last month announced proposed Federal 
standards for data communications interfaces; the proposed standards 
specify the general purpose electrical characteristics to be applied to 
data comrnunicatons interfaces. 
The National Science Foundation [NSF] last motlth said several of its staff 
members hyve been appointed to provide initial support for the Office of 
Science and Technology Policy (OSTP). 
The first Federal $oft?&&; Excchg.e CataZog, designed to promote the exchange 
and sharing of software among ~ederal AW units, is-scheduled to be re- 
leased th$s January by the Agency Services Division of the General 
- 
Services Administration (GFA) . 
The Bure,au of the Census last monthanounced the availability of a 584-page 
report, tit led Conputer Pwgrwns for Demographic Analysis (p --enclose 
$5. SO), first published last June. 
The Na'tionql Bureau of Standards (NBS) is holding a Bicentennial Conference on 
MathematkaZ Progdng November 29 through December 1 in Gaithersburg, 
Md.; the conference is being co-sponsored by NBS and the ACM Special -. 
Interest Group on Mathematical Programming (SIGMP). 
AFIPS IN WASHINGTON 
A Planning Conference to provide technological background for the second FCC 
"Computer Inquiry, tt organized by AFIPS in conjunction with the FCC (Wushinqton 
Report, 10/76) , was convened in Washington November 8-9. The conference focused 
on computer communications, especially as it relates to regulatory policy. 
Detailed coverage will appear in the December AFIPS Washington Report. 
WASHINGTON OFFICE ACTIVITIES DESCRIBED AT DPMA INFO/EXPO '76 IN IAS VEGAS 
AFIPS Washington Office Director Philip S. Nyborg last month chaired a panel 
session on major activities of the Washington Office at the DPMA INFO/EXPO '76, 
in Las Vegas October 26. The session covered the Office's activities in such 
areas as privacy, EFTS, legal protection for softwere, computer security, data 
conununications , and technology transfer. 
The panel opened with a discussion of the historical perspective of the office 
and its outlook for the future by Mr. Keith Uncapher, chairman of the AFIPS 
Washington Activities Committee. Nyborg f o1,lowed with a description of the 
dai ly operations of the Office, outlining the manner in which comment has been 
organized by AFIPS on specific issues. 
Mr. William Moser, DPMA International Vice President for Industry and Govern- 
ment Liaison, described his role as DPMA liaison to the Washington Office. 
Moser emphasized his interaction with DPMA members h devs Isping comment on 
testimony , and he encouraged their continued participation. 
Dr. A. Michael Noll, formerly the staff member for computers in the White 
House Office of Science and Technology (OST), described past and present 
Presidential science advisory mechanisms. No11 ' s presentation also covered 
the new Office of Science and Technology Policy, and its potential relation- 
ship to the field of information processing. 
The AFIPS Washingtom Report is researched and written by Pender M. ' ~ccarter, 
Research Associate, AFIPS Washingtcn Office. 
AFIPS societies have permission 
to use material in the AFIPS Washington Report for their own publications, 
except where an article title appears with an 
clearance must first be 
obtained from the AFIPS Washington Office. Documents indicated by the symbol 
are available on request to the AFIPS Washington Office. Where price is 
noted, make checks payable to IrAFIPS."' 
? 
Phlllp S Nyborg, D~rector 
Wash~ngton Office 
dw Washington Report 
************-*************************** 
Arnerlcan Federabon of lnformatton Processing SOCI~~I~S, lnc , Sum 420, 2100 L Street, N W Washington, D C 20037 202-296-0590 
Vo1. 11, NO* 11 
December, 1976 
WASH1NC;IYIN DEVELOPMENTS 
FEDERAL HOME LOAN BANKS, FHLBB APPEAL RULING PROHIBITING DP SERVICE OFFERINGS 
BY BANKS 
Federal Home Loan Banks in Cincinnati, New York, Chicago, Pittsburgh and 
Des Moines have joined Washington's Federal Home Loan Rank Board (FHLBB) to 
appeal a September ruling by a Federal District Court Judge in Cincinnati 
that Federal Home Loan Banks can not provide computer services to savings 
and loan associations. Five of the 12 regional Home Loan Banks, which are 
or at one time have been suppliers of data processing services, are involved 
in the Cincinnati appeal. 
ADAPSO, United Data Procesahg obtain irr;junct;on. The original case was 
brought against the FHLBB and a Cincinnati Home Loan Bank by the Association 
of Data Processing Service Organizations (ADAPSO) and United Data Processing, 
Inc, In October, 1973. The remaining four Home Loan Banks joined the suit as 
intervenors in November, 1973. The district court ruling enjoined all five 
banks from offering data processing services beginning January 1, 1977. A 
modified stay of the injunction has been obtained by the FHLBB pending the 
present appeal. 
District court bZds that FehZ Rome Loan Banks aro not permitted to provide 
D In the original suit, ADAPSO argued that the Federal Home Loan Banks 
posed "a form of unfair competition1' to private enterprise because they are 
exempted from taxat ion. William W. Fletcher, president of Midwest Advanced 
Computer Services, inc., Warren, Mlcigan, and ADAPSO member, has been quoted 
as saying that hls firm can not compete with the Federal Home Loan Banks I 
"30 per cent lower" rates. In addition, ADAPSO said that the PederaZ Rome 
Loan Bank Act of 2932 forbids banks from participating In nonbanking commercial 
activities such as those provided by computer service centers. 
Federal District Judge Carl B. Rubin, in his ruling last September, held that 
"the providing of data processing services to member institutions is not an 
express power granted to the Federal Home Loan Banks or Federal Hone Loan Bank 
Board1' by the FedsmZ Home Loan Bunk Act. ADAPSO Executive Vice-President 
Jerome L. Dreyer has criticized the FHLBB for encouraging its members to market 
data processing services to the same banks which the FHLBB regulates. 
Further adverse court ruzings eouM proscribe future DP offerings by Home Loan 
Banks. ADAPSO Attorney Herbert E. Marks, who is handling the FHLBB case, told 
AFIPS Phshington Report that the New York Federal Home Loan Bank has ceased 
offering data processing services since the district court injunction was 
obtained. Marks noted that further adverse rulings against the Home Loan Banks 
could proscribe future data processing offerings by the seven other Federal 
Home Loan Banks. He also said that if the district court is upheld by the 
appeals court in Cincinnati, the Federal Home Loan Bank Board could appeal to 
the Supreme Court. 
A spokeswoman for the FHLBB in Washington told AFIPS that the FHLBB had no 
comment on the case since it is in litigation. 
She stated that the New York 
Federal Home Loan Bank ceased providing data processing services prior to the 
district court ruling, not after the injunction, as Marks contended. 
NEW CBCT REGULATIONS MAY SANCTION OPERATION OF ,NON-FEDERALLY REGUtATED EFTS 
TERMINALS 
Acting Comptroller of the Currency Robert Bloom last month announced new 
customer-bank comntunicat ions t erkninal (CBCT) regulations for national banks. 
The new regulations allow national banks to apply for permission to establish 
CBCTs as branches in states where state-chartered banRs are permitted to 
establish branches. Bloom's action follows the Supreme Court's refusal to 
consider consolidated petitions from two Chicago banks and the Comptroller of 
the Currency seeking review of Federal Appeals Court decisions which equate 
CBCTs with bank branches and forbid CBCTs in non-branching states (Washington 
R6pPt, 11/76]. 
The Comptroller has unsuccessfully argued in the courts that CBCTs are not 
branches, and are not forbidden in states which limit or disallow branching. 
The trade press suggests that the new regulations may sanction the operation 
of non-federally regulated EFTS terminals by retailers, shopping mall operatorsf 
owners of apartment complexes, or operators of transportation terminals. Thus, 
the effect of these regulations may be to extend the present list of EFTS 
ilprovidersff beyond financial institutions, i.e., to include what were formerly 
on13 EFTS users. 
The Comptroller's new regulations state that capitalization required for a 
CBCT branch may now be shared among the participants, thus lowering the cost of 
operating a CBCT, and presumably making CBCTs available to smaller banks with 
less capital (see Washington Report, 11/76). Also, in contrast to the $500 
application fee for a traditional branch, the application fee for a CBCT branch 
is $200. 
In the section of the Acting Comptroller's statement, said to sanction operation 
of non-federally regulated EFTS  terminal^, Bloom held that "any CBCT which is 
not established by a national bank . . . is not a branch of a national bani, 
and not subject to the provisions oftf the applicable section of the federal bank 
regulation, the McFadden Act, which the courts have held forbids CBCTs in non- 
branching states . 
WHITE HOUSE ANNOUNCES APPOINTMENTS TO PRESIDENT'S COMMITTEE ON SCIENCE AND 
TECHNOLOGY - 
The White House has announced appointments to the President's Committee on 
Science and-Technology [PCST), which will conduct a two-year review of science 
and technology as it relates to the Federal government. 
The Coanittee was created by the same legislation [WaehCngtm Report. 5/76) 
which established the new White House Office of Science and Technology Policy 
[OSTP). 
As previously announced, the chairman of the committee is Dr. Simon 
Raao, co-founder of TRW. Inc. Vice chairman is Dr. William 0. Baker, president 
of Bell Labs. Both Rmo and Baker were chairmen of cornittees organized last 
year by President Ford to plan for OSTP. 
Other members of the PCST are: Otis R. Bowen, governor of Indiana; W. Glenn 
Campbell, director of the Hoover Institute on War, Revolution and Peace, 
Stanford University; Edward E. David Jr., vice president of Gould, Inc., and 
former science adviser to President Nixon; Elizabeth H. Leduc, professor of 
biology, Brown University; Fritz J . Russ , president, Systems Research Labor- 
atories, Dayton, Ohio; Charles P. Slichter, professor of physics, University 
of Illinois; Charles H. Tomes, professor of physics, University of California 
at Berkeley; and W. Bradford Wiley, chairman of John Wiley and Sons. 
FEDERAL ENERGY ADMINISTRATION ASSISTS WITH COMPUTERIZED CONSTRUCTION FORE,- 
CASTING SYSTEM 
The Federal Engergy Administration (FEA) is assisting in developing a computer- 
based system to permit national and regional projections of construction labor 
needs in relation to energy development. The system will also provide long 
and short-range forecasts in local areas, FEA Administrator Frank G. Zarb said 
last month. It will be implemented late next year, Zarb added. 
NATIONAL SCIENCE FOUNDATION RELEASES GUIDE TO PROGRAMS REFLECTING APPROPRIATIONS 
The NationaL Science Foundation INSF) last month released its Guide to Programs 
(#-- enclose $1.353 reflecting NSFts appropriations for FY 1977. Programs in 
theoretical computer science, software systems science, software engineering, 
intelligent systems, computer systems design, and special projects are described. 
Proposals for support are ordinarily assigned to the appropriate NSF division 
or office for review and evaluation. 
The theore ical computer science program encompasses the theory of computation, 
numerical analysis and computational ~nathematics , theory of formal languages, 
and analysis of algorithms. The software systems science program covers 
"f~ndamental'~ questions of communicating with and controlling computer syszems. 
The software engineering program includes the methods, tools, and techniques for 
specifying, designing, and implementing 'lqualityl' software. The intelligent 
systems program covers computer-based systems which have such characteristics as 
pattern recognition, pattern generation and knowledge representation. 
The computer systems design program includes the principles of computer systems 
design such as: computer system architecture, performance, graphics, man-machine 
interaction and logic design. The special projects program encompasses 
research projects, studies, workshops, and other activities which '?miBht 
encourage the development of new fields of computer science research." 
Should future legislation result in some modification to the FY 1977 program, 
changes will be announced in the monthly ASP BuZZsth~. 
Program schedules, 
deadlines, updates, and availability of brochures describing individual programs 
ape also published in the BuZZetdn. 
It may be obtained free-of -charge by 
writing: 
Editor, NSF BuZZetin, Public Information Branch, NSF, Washington, D.C. 
20550. 
NEWS BRIEFS 
65 
The 
at press time late last month reversed the Chief of the Common Carrier 
Bureau's rejection of ATqT's Dataspeed 40/4 filings (Washington Report, 
4/76) ; the Commission concluded that the 40/4 service is "not inconsistent1' 
with its existing computer rule; detailed covWaga will appear next month. 
FCC Chairmum Richard 8: wiiey early last mnth said the - FCC is-considering 
whether it has authority to ask the courts to modify the 1956 ATeT anti- 
trust consent decree; the Justice Department has held that the consent decree 
bars AT4T from interstate marketing of the telephone company s Dataspeed 40h4 
as "incidental" to regulated communications, 
The director of the White House Office of Telecomunications Policy @W] , Thomas 
J. Houser. last month criticized the Federal Reserve System for emandinn - . . - - - - . - .- -. - - - - . . . - - - - . - . . 
" 
"its operit ional role in interbank EFT with pilot pro j bctslt linki& automated 
clearing houses (ACHs) with telecolmnmications (Washington Report, 9/76) ; 
however, H. L . Baynes , president , National Automated Clearing House Association 
(NACHA], which is operating the project with the Federal Reserve, told this 
writer last August that the Fed has "the right to develop an ACH processing 
capability [and to go] interregional without involving the private sector. 
The General Services Administratioq (GSA) last month amended its Mvaoy Gu--&de- 
Zines adding privacy ad security considerations for use in ADP or tqlecom- 
municat ionsT$st ems solicitat ioki and corntracts ; the amendments also require 
that agencies provide an inspection program in system specigications and 
contracts that will ?'ensure coptinuous, efficacious and efficient safe- 
guards, and provide for the discovery and the countering of any new threats 
or hazards. " 
The National science Foundation [NSJSP) last month said indtutrial spending for 
research and development reached $23.5 billion in 1975, up five per cent from 
the 1974 level of $22.4 billion. 
A study which lists fffactors important to successit in the mainframe computer 
industry, titled The American Capzrter Industry in ite Intsrnat$omZ Covet- 
it4ve Grzuirommt (#--enclose $1.70) was released last month by the Domestic 
and International Business Administration of the Department of Commerce. 
Information which may be needed by managers considering data base implementations 
is featured in Data Bass L%reotions--The flext Steps (#--enclose $2.401, a 
158-page special publication of the National ~ureau of Standards (NBS~, first 
announced last October; the document incorporates the Proceedings of a 1975 
workshop co-sponsored by NBS and the ACM. 
li- 
The NatiomZ C<viZ Serv&?s LeagUeCareer SsrzJ%ce Award for 2976 was presented last 
month to Dr. Ruth M. Davis, Director of the Department of Commerce's National 
Bureau of Standards CNBS) Institute for Computer Sciences and Technology (ICST) 
AFIPS IN WASHINGTON 
FCC COMPUTER COMJNICATIONS PLANNING CONFERENCE: 
'NO LOGICAL TECHNICAL BOUNDARY' 
BETWl!EN COMPUTING AND CO~ICATIONS 
Summarizing the technical presentations at the FCC P~unning C'onfermee on 
Comter Colmnurica6~ons Novenber 8-9 in Washington, organized by the AFIPS 
Washington Office, rrr. Vinton G. Cerf of the Information Processing Techniques 
Office, Defense Advanced Research Projects Agency (ARPA] , noted: (1) There is no 
"logical technical boundary'? between computing and communications; (2) Packet 
switching is having an ttimportant effectw on computer comnmications today, and 
will have a ftprofound effect" on frequency allocation in the future; (3) High 
local access costs, international link costs, and user learning costs are 
(Ilimiting" the growth of computer communications services; (4) The prime opportu- 
nities for network costs and tariff improvement lie in the development of new 
facilities for local access and for intercontinental links; and (5) A regulatory 
climate is needed "which encourages innovation, ensures reliable interconnection 
of primary services, and promotes the acquisition of capital for growth.11 
Witey says FCC p02ioy deoisions must be bused on under8tunding of technoZogy. 
Opening the conference, FCC Chairman Richard E. Wiley stated his view that a 
computer is a comunications device, not a data processing device, when it is used 
in a traditional communications service. However, Wiley also noted that the use 
of computer technology may result in an enhanced service, offering more than 
traditional communications. 
He predicted that Similar technological forces will develop in several areas of 
communications service. Wiley said: "1 firmly believe that, in this grbat free 
enterprise society of ours, government regulations must not be permitted to stand 
in the way of thchnological development. If the new technology creates adminis- 
trative difficulties for the government, it is the regulations that must be 
conformed and not the technology." 
According to the FCC chairman, "We will see more instances in the future where, 
as here, the technology is developing in a manner that blurs traditional inter- 
faces. In cases of this sort, the policymakers mu8t have direct access to 
technical experts and decisions must be based upon an understanding of the 
technology. 
Wiley also said, "It is our belief that AFIPS is a particularly appropriate 
entity to present this conference fur the Commission, in view of the Federation's 
sponsorship of the National Computer Conference, and the Joint Comput el' Conferences 
prior to that. Moreover, it is also our view that AFIPS is a basically impartial 
organization in relation to our policy concerns,bringing to us the objective views 
of a group of highly qualified experts .'I 
Computer communieutions aceaunts for 20 per cent of a22 acpenditmes in computgr 
fietd. In the conference Is first presentation on "Computer Communications ; An 
Introduct $on and Overview ," Lynn Hopewell (chairman, IEEE Computer Society 
Technical Committee on Computer Communications ; and senior member, executive staff , 
Coihputer Sciences Corp.] said that computer communications systems had first been 
used in control I i n g ~lcomplexfl operations of industry and government. Hopewell 
added that the most common use of computer commun2cations is in data base applica- 
t ions. 
The speaker suggested that the computer communications industry accounts for 20 
per cent of all expenditures in the computer field, Examples of industrial areas 
affected by computer communications technology were listed as law enforcement, se- 
curities brokerage, insurance, reservations systems and banking. Hopewell said 
that 75 per cent of the top 500 industry corporations are now using camputer 
communications. 
Distributing samples of a microcomputer-on-a-chip , he noted technological changes 
that have produced a 1976 microcomputer CPU costing $20 in contrast to a 1960 IBM 
CPU costing $30,000. 
Hopewell added that microprocessors which cost $20 today 
cost $100 only a year ago. 
He indicated that such differentials represent only 
the beginning of extremely low cost computing. 
Hopewell said that the proposed definitions employed in the new "Computer Inquiryff 
aid in qlclarifying the permitted uses of computers by common carriers, but in 
no way allow the proposed abandonment of the 'hybrid1 service concept 
He 
noted that the hybrid concept should be retained "because some service offerings 
have mixes .ob both computing and communications  function^,^' not because of un- 
clear definitions. 
Since "hybrid services will become even more common in the future," 
Hopewell 
continued, elimination of the hybrid concept will "ineyitably suppress innovation 
because any services that have communication factions inextricably bound into 
them will be defined as subject to regulation." The speaker concluded that he 
saw no "technological or economic reason for the regulation of the resale industry.?l 
Te~htu,Z~gy $8 'mov;ng td8 tntegmted &deband 8ehes. ' 
In his presentation 
on "Research Topics in Computer Conwnmicati~n ," Vinton G. Cerf summarized 
t ethnological factors influencing the development of computer comhunicat ions, : 
the 
availability of wideband transmission media; the use of computers to control the 
switching and allocation of transmission bandwidth; the trend towards all-digital 
telephone networks; and interconnection of computer cornmuhications networks. 
Cerf said the "technology is leading away from separate, distinct narrowband 
services . . twoards integrated widenband services. The potential social impact 
is pervasive; the possibilities for new wealth-creating activity, almost incalcu- 
lable; and the need for regulatory adjustment, inevitableeft 
With the juxtaposition of computing and connnunication, he suggested the FCC could: 
reallocate the radio spectrum using computer-controlled demand access; mandate 
computer communication network interconnection through the enformcement of inter- 
connection standards; and consider proposals by =plated carriers as well as 
others "to provide previously impossible combinat ions of information processing 
and traditional communication services. 
'Boundary betueen corrmunicat~ng und computhg wit2 become mare bZurred. ' In his 
presentation on the MDimensions of t&e Need for Computer Communications ," Alex 
Cupan, president, BNR, Inc., suggested that domestic users must seek to reduce 
the cost of network access for smaller users, especially in the ltsmaller urban 
centers .'! FCC Interconnection Chief Louis Feldenr , in a question-and-answer 
period following Currants presentation, stressed the Itneed for computer powervf in 
rural areas. 
In his formal presentation, Curran continued that the cost of intercontinental 
transmission must also be reduced. According to the speaker, these measnres 
would help to insure that Ifthe common carrier networks can cope with the data 
communications traffic of commercial users.11 
Curran stated that some of the office and home services associated with computer 
communications could require reintegration of voice and data capabilities. 
He 
provided several current examples of personal computing including: 
Vieuduta, the 
embryonic electronic newspaper in the' United Kingdom; Icasthzg, instantaneous 
voting and data collectio~~ in Canada; MzCZgram, a precursor of electronic mail in 
the U. S.; and CAJ, computer-assisted instruction. 
Curran also said that other services will require switching machines "capable 
of recognizing information [interest] specifications as valid addresses 
For 
example, swi thcing machines could recognize selective informat ion dissemination 
interest profiles as valid addresses, he noted. Curran concluded : 'Thus, the boundary 
between communicating and computing will become more blurred. There are 
economic arwents for suggesting that the boundary definitions be relaxed 
to encourage a new cycle of innovation 
FCC decisGm8 my ZMt the growth of carr%ers, not necessaAZy the g~oth 
of wegu&%t@d supptiero in data pmoeseSng. In his presentation, titled 
frLimitations on the Growth of Computer-Communication  service^,^^ Prof. Donald 
A. Dunn, Engineering Economic Systems Department, Stanford University, 
indicated that user learning costs will limit the rate at which new computer 
~ommunication services can be introduced to markets serving non-computer pro- 
fessionals. Dunn suggested that, in future regulatory decisions, integrated 
service packages (designed to minimize user learning and operation costs) 
might be used in lieu of individual component services as the unit of,service 
that is judged cohnnunications or data processing. He added that regulatory 
limitations 'on the rate of return and regulatory policies on depreciation 
allowances can restrict technological change as well as limit the rate of intro- 
duction of new equipment by carriers. 
According to the speaker, the earliext ftComputer Inquiry" rule, requiring data 
processing $entices to be provided by carriers through a separate affiliate, may 
limit the growth of carriers. But he added that the rule does not affect the 
growth of the data processing industry since unregulated suppliers can respond 
to this market. Dunn also noted that the resale and sharing decision, imposing 
regulation on resale carriers, would not necessarily inhibit the growth of the 
industry Itsince separate data processing affiliates will not be required of 
resale carriers that do not provide monopoly services." 
He stated that the resale and sharing decision "removed some of the most serious 
limits to the growth of this industry by opeining the market for network services 
to essentially any firm willing to operate as a resale carrier." Dunn concluded: 
"Pressures are likely to develop soon to regulate providers of information service 
packages that may offer computer message services to users that obtain network 
service from resale carriers. Such regulation would inhibit the growth of the 
industry, and is not needed to protect the interests of users. lf 
"There is no mtmZ bozbzdary' bsttdem cormnm~cat<ons and computtnq. In their 
presentation on "The Future of Computer Communications ." Vinton G. Cerf and Alex 
Curran said that "we cannot offer a solution to the definition of a boundary 
between communicating and computing--in fact, technical considerations convince 
us that there is no natural boundary." 
Cerf and Curran urged the FCC to support the development of ffcompetitive servicestt; 
to insure that a ''sufficient setf1 of standards is created to facilitate inter- 
connection of 'prime servicesf1; create a climate in which both computing and 
carrier interests profit from the installation of "reliablefv facilities; and 
broaden the base for the acquisition of capital so as to eliminate a possible 
constraint on growth. 
Conference preeenutiom oiZZ become prt of fumt record of Caputer InquCry. 
The conference, open td the public, was attended by over two hundred people, 
including those who watched the proceedings via closed circuit television in an 
adjoining room. As previously announced. the presentations will become part of 
the formal record in the FCC's tlComputer Inquiry.'l A Proceedings containing all 
the papers is available at $10 per set from AFIPS Headquarters, 210 Sumtit Avenue, 
hlontvale, New Jersey 07645. Headquarters telephone number is (201) 391-9810. 
AFIPS PAN)% mMsEM COktbfENT ON USE OF SOCIAL SECURITY NUMBER AT REQUEST OF 
PRIVACY COPMISSION 
Members of the AFIPS panel on private sector usage of the Social Security Number 
(SSN) , organized at the request of the Privacy Protection Study Commission 
(washington Report, 2/76) , last October responded individua lly to a staff memo 
copcerning the use of the SSN, submitted to them by Privacy Commission Executive 
Director Caroler W. Parsons. 
Daniel D. McCracken, independent consultant, said he favors legislation ?'to 
prohibit unauthorized matchihg of records" through use of the SSN as a universal 
identifier . McCracken wrote Parsons, saying that lacking such legislation, "1 
would argue for restrictions on the use of the SSN as a partial subsititue, and 
as a way to keep the more basic issue alive and visible." McCracken, who is ACM 
vice-president, is responsible for passage of an ACM resolution opposing the use 
of the SSN as a universal identifier., 
Herbert S. Bright, president, Computation Planning Inc., who also filed a response 
to the memo, said use of the SSN in licensing drivers opens SSN files to insurance 
companies as well as list compilers and 6ther vendors. Bright added: "Continuing 
progress in cross-linking practice between insurance companies is increasing the 
justification for vigorous efforts by the Commission to examine such attacks on 
privacy and to place the facts before the public and the Congress ." Bright is 
also a member of ACM. 
Willard E. Hick, auditor, Massachusetts Mutual Life Insurance Co., Springfield, 
Massachusetts, responding to the memo, wrote that the Commissionts statement 
supporting continued use of the personal identifier tlshould emphasize need and 
not conaentrate on counteracting sugges*ions that have been made .I1 Hick questioned 
why the Conunission does not "address in more detail the reason universal 
identifiers are necessary on a positive rather than negative note." He told 
AFIPS Washington Report that, to the best of his knowledge, there is no I1cross- 
linkingw between insurance companies. Hick is a member of the Institute of 
Internal Auditors. 
Also responding to the memo, with letters not available at press time, were: 
Jeffrey V. White, president, The Credit hreau, Inc., Atlanta, Georgia; John J. 
Stiglemeier, director, Information Center on Education; Roger E. Creel, assistant 
vice president-Syst ems 6 Processing, Employers Insurance Co. of Wasau, Wausau, 
Wisconsin; Alden R. Dalzell, director of Data Processing, Ohio University, Athens, 
Ohio; J. M. Moore, section head, Exxon Corp., Florham Park, New Jersey; and 
William E. Perry, director of EDP and Research, the Institute of Internal Auditors, 
Orlando, Florida. 
-- 
-> - - -- -- - - ---- - ----- 
Am Washington Report is researched and writte a by Pender M. McCarter, 
Research Associate, AFIPS Washington Office. 
AFIPS societies have permission 
to use material in the MIPS Washington Report for their own *publications, 
except where an article title appears with an If(*)," clearance must first be 
!obtained from the AFIPS Washington Office. 
Documents indicated by the s];sbol 
'"(ff)" are available on request to the AFIPS Washirgton Office. 
Where price i 
\noted, make checks payable to "AFIPSal! 
d@ Washington Report 
f**********J********************rk****** 
Amer~can FedBrat~on of Infdrmahon Prmsdng Soc~etles, Inc , Su~te 420, 2106 L Street, N W Wash~ngton, D C 20037 202 296 0590 
Vol. 111, No. 1 
January, 19:7 
WAS1 IINGTON DEVELOPMENTS 
FEDERAL DATA ENCRYPTION STANDARD APPROVED BY COMMERCE DEPARTMENT 
A data encryption algorithm, designed to protect digital information, was 
approved in November ad a Federal .Information Processing Standard (FIPS) 
by the Department of Commerce. The new standard will be described and 
promulgated in FIPS PUB 46. 
The algorithm was first proposed by the Institute for Computer Science 
and Technology (ICST) of the National Bureau of Standards (NBS') in 1973. 
The encrypt ion algorithm converts informat Ion into -an encoded [C. e. , encrypted) 
form which can be transmitted or stored, but which cannot be read without the 
appropriate key. Thus, it can be used to protect inforfiation communicated 
between a terminal and a computer, as well as between computers; in addition, 
it can be used to protect information stored in off-line media. 
Mandatory stundiud for Federa2 agewies. As a FIPS, Federal agencies wlll 
be requ~red to use the encryption algorithm, whenever encryption of data is 
deemed necessary. However, data subject to the ilu:iona2 Security Act of 1967 
and the Atomic Enenergy Act of 1952 are exempted from the standard. The 
encryption algorithm may also be used on a voluntary basis by organizations 
and individuals outside the Federal government. 
Primary initial appJication in EFTS. The new standard's primary application 
is, initially expected to be in Electronic Funds Transfer Systems [EFTS). The 
algorithm can be employed in EFTS to discourage l1skinuning" of bank card 
information for the purpose of gaining access to automated teller machines 
(ATMs). It can also be employed to prevent interception of compute1 messages 
authorizing transactions at the ATM. Several non-standard encryption 
algorithms, including one developed by Diebold, Inc,, are already in use by 
some banks. 
Strength ofaZgcwith estimated. NBS said technical workshops have been held 
to measure the strength of the algorithm in terms of time and money that must 
be spent in finding the key. In November, at the Dartmouth College Symposim 
on Man and the Computer, ICST Director Dr. Ruth M. Davis stated that, while 
go code is ~theordtically unbreakable," 2,500 years of computer tine on a 
general-purpose computer Ilslgnlficantly faster" than a CDC 7600 would be 
required to derive a key. With respect to future technology, Dr. Davis 
estimated that "working from matched sets of clear and clpher data, well over 
$300 millionH could be spent five years from now to find a key. With technology 
available in 10 years, it could take $70 million to derive a key, she said. 
IBM 'e cr~~orithm choeen; compan%es to manufauture devices $morporatl'ng 
c~ta?t.durd dthuut paying royuztiee. 
ICST began soliciting encryption 
algorithms in 1973 and 1974. 
IBM's proposed algorithm was chosen in 1975. 
While IBM has patent rights in the standard, the company has .agreed to 
grant royalty-free licenses to other companies which wish to manufacture 
devices incorporating the algorithm. 
The trade press notes that Motorola 
an& Rockwell ~nternational are planning to manufacture integrated cirduit 
chips which incorporate the encryption algorithm. 
Stundcql -too be pubtished 2/I5/77; oonfepeme echeduted. 
PIPS PUB 46 is. 
expected-to be published February 15, 1977. and to become effective Augrut 
15, 1977. Copies of the standard will be available after February 15 from 
the National Technical Informatibn Service (NTIS), DOC, 5285 Port Royal Roa& 
Springfield, Virginia 22161, or through the MIPS Washington Office. 
NBS will 
hold I conference on February 15, 1977, at its Gaithersburg, Maryland, 
facil~tiss to discuss !'IPS PUB 46 in relation to other security measures, 
TERMINAL MANUFACTURERS, INDUSTRY ASSOCIATIONS CRITICIZE FCC APPROVAL OF 
DATASPEED 4014 
Independent terminal manufacturers and industry associations Bast month 
criticized the Federal Communications Commission (FCC) for its approval of 
tariff filrings on AT&Tts Dataspeed 4014 terminal device (Washington Report, 
12/76). me FCC's approval, announced in November, reverses a previous 
proposed decision by the Commission's Common Carrier Buresd. which rejected the 
Dataspeed 40/4 tariff (Washington aeport, 4/76). Under the new FCC ruszng, 
ATGT will be permitted to provide the Dataspeed 4014 service. 
Primmy Issue. pe debate centers on whether the terminal bffering constitutes 
a data communicat~ons service or a data processing service. If it is a data 
conununications service, as held in the present donunission ruling, ATGT can 
provide the service. However, if it is a data processing service, as the Chief 
of the C~mon Carrier Bureau stated last March, ATET cannot provide the service 
The FCC had held earlier in its original lvCompute]r Inquiry" that common 
carriers may pr(wi.de data processing services, but only through unregulated 
subsidiaries. However, AT&T is even pre6luded. Zrom this option by its 
agreemept in a 1956 consent decree (with the U.S. Department of Justice) not to 
participate in unregulated industries. 
Specific industry criticism. The independent terminal manhfacturers and 
computer industry groups charged that the development of the Dataspeed 40/4 
terminal is subsidized by profits from ATGT's regulated communications service 
offerings. Thus, they contend that the device represents "unfairff competition 
by ATGT against unregulatedb industries. 
Possible further aeth. The FCC has stated that its latest ruling is 
contingent on the outcome of the Comrnissionts new 'IComputer Iuquiryvt (see 
Wash6zgtun Report, 8/76). (Comments in this proceeding are now due April 11, 
1977; replies are due May 25, 1977.) However, the trade press speculates that 
it is unlikely that the Dataspeed 40/4 offering, once tariffed, will be 
"detariffedat' 
The Computer and~Communications Industry Association [CCIA) has indicated its 
intention to file suit against the Commission in the U.S. Court of Appeals in 
the District of Columbia. CCIA seeks to enjoin implementation of the FCC's 
ruling, pending a full wurt review on the merits. 
CCPA APPROVES PATENT FOR SOFTWARE PROGRAM SECOND TIME 
Some software programs are eligible for patents, according to the U.S. Court 
of? Customs and Patent Appeals (CCPA), which last November reversed %he U.S. 
Patent Office for the second time on the issue of software patentability. 
The CCPA decision involves the l'Regulatort' program (developed by Glen F. 
Chatfield, president of Duquesne Systems, Incl), whfch adjusts the priorities 
op computer programs. 
In two previous cases, the Supreme Court (prior to the latest Chatf5eZd 
decision)has reversed the CCPA, deciding in favor of the Patent Office on 
limited grounds and not addressing the question of software patentability. 
In CottschaZk v. Benson, the Court ruled four years ago 'that a program to 
convert binary-coded decimal was not a patentable llprocessh as defined in ttie 
U.S. Code, In 'Dann, ComrnissZoner of Patenes ad Truemarks v. Johnston, the 
Cmrt held last April (WashCngton Report, 5/76) that a computerized record- 
keeping system, developed for banks by Thomas R. Johnston, is ltotnrious to one 
reasonably skilled in [the applicable] art, and is therefore not patentable. 
CCPA Chief Jud e Harold T. Markey ruled in the ChatfisZd case that "no prior 
art was cited f by the Patent office] against the appealed claims, and, 
accordingly, [the] invention must be considered to have been new and unobvious." 
The judge also held that' Chatfield's invention meets the U.S. Code requirement 
for tlpro~e~~'l claims. 
TELEPROCESSING SERVICE PROGW INITIATED BY GSA, TO HELP REDUCE $10 BILLION 
FEDERAL DATA PROCESSING BUDGET 
The General Services Administration (GSA) in November signed its first two 
teleprocessing services schedule contracts, permitting agencies to order 
services at government-wide volume discounts!, rather than make separate 
procurements at greater cost. The contracts, effective December 1, provide 
for interactive and remote batch proc'essing services &timated at between $50 
to $80 million over the next year. Computer Network Cow. and First Data Corp. 
received the first two contracts. 
The trade press suggeststhat the teleprocessing services program is the fi~st 
of several steps the Government is implementing to reduee its $10 billion in 
yearly expenditures on data processing. For example, the Office of Management 
and Budget (OMB], Executive Office of the President,is encouraging greater use 
of outside service bureaus as well as third-party leasing firms. In addition, 
each Federal agency has been directed by OMB to determine five operations now 
being performed on its own computers that could be performed on service bureau 
computers. 
OMB is expected to continue ~ts moves to cut DP expenses through the 
transition t~ the Carter Administration. 
@lNSUMER BENEFITS IF EFT TERMINALS ARE NOT CONSIQERED BRANCHES: 
NCEFT 
TELLS SENATq 
Members of the National Commission on Electronic Fund Transfers [NCEFT) last 
month told a Senate Subcornittee that the Arner1ea.n consumer "may suffer 
unnecessary inconveniences and may pay higher prices for payment services" 
if EFT terminals are governed by the saw, laws and regulations that apply to 
bank branches. 
Such Federal laws equate EFT terminal's wiTh branches thus 
forbidding EFT terminals in non-brandring states. 
[See Wash5ngton Repop** 
12/76.) 
In testimony presented to the Subcommittee on Financial Iristitutions, chaired 
by Sen. Thomas d. McIntyre (D-N.H.), NCBFT Chairman William B. Widnall and 
Executive Director John 0. Benton agreed that "[tlhe greatest current impediment 
to putting into place the technology which can provide the benefits of EFT to 
the consumer is the uncertainty which exists about the legal environment within 
wllich EFT systems will operate in the future." The chairman and executive 
director, joined by three NCEFT commissioners, said that a competitive 
imbalance is created when federally-chartered savings institutions have greater 
freedom in deploying EFT terminals than national bahks,which are governed by 
more restrictive legislation. The NCEFT representatives+ added that business 
enterprises, such as retail chains, "should not be considered , , . regulated 
institutions or branches thereof," when they employ electronic terminals to 
communicate with depository institutions. 
Last month, the NCEFT convened hearings on competition and sharing. The 
Commi$sionfs interim report is due February 23. 
RGD HAMPERED BY LACK OF COOPERATION BETWEEN GOVERNMENT, PRIVATE ENTERPRISE: 
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"Lack of teamwork between the Government and private enterprise is the number 
one bottleneck in the nation's pursuit of research and development," said 
Dr. Simon Ramo, vice chairman of the board and chairman of TRW, Inc. Speaking 
last November in Washington at the annual fall meeting of the National Academy 
of Engineering, Dr. Ramo added, "Even the nation's most capable researchers 
spend much of their time defending their selection of projects and describing 
potential results, rather than in carrying on research. We are persisting in 
this tendency even with growing indications that the U.S. is losing its leader- 
ship position as to the fraction of gross national product being devoted to basic 
research." The TRW Executive, who is also chairman of the President *s Science 
and Technology Committee,expressed the hope that the new Office of Science and 
Technology Policy, Executive Office of the President, will contribute to the 
formation of llsoundlt national policy. 
ASST. COMMERCE SECKETARY RECOMMENDS USPS COMPROMISE ON-PAGE CHARGES FOR NON- 
PROFIT SCIENTIFIC, ENGINEERING, AND TECHNICAL JOURNALS AND PERIODICALS 
The U.S. Postal Service (USPS) is ItwillSng to modify1' the USPS regulation 
requiring reading matter in all non-profit, second class publications to be 
marked ~ladvertisementv when contributors are required to pay page charges on 
their submissions, Dr. Betsy Ancker-Johnson, 
the Department of Commercets 
Assistant Secretary for Science and Technology, 
last month said the USPS is 
llwilling to modify the regulation so long as contributions to publishing costs 
arenlt mandatary but vol~ntary.~' 
Convening a meeting last month of the Committee on Intellectual Property and 
Information, Federal Coordinating Council for Science, Engineering and 
Technology, Dr. Anclcer- Johnson, committee chairman, indicated that this 
voluntary arrangement should be clarified in the publicationts masthead. 
The regulation could affect the policy of AFIPS constituent societies which 
must publish a non-profit j ournal as one qualification for membership. 
Page charges, paid by researchers, are viewed by journal publishers as one 
method of defraying the cost of reporting research. In many cases, page 
charges are paid by funds obtained through research grants. Charges may be 
voluntary,far example, with researchers who are not supported by grants. 
Dr. Bernard Forscher, managing editor of the National Academy of Sciences' 
Prooasdhgs, suggested in an interview with AFlPS Washington Report, that page 
charges should be considered in research budgets. Dr. Forscher compared publi- 
cation of research findings with "staking a claim to a disc~very,~~ or "obtaining 
a deed." Forty per cent of the production costs of the ProoeedjnSs are defrayed 
through page charges; the remaining 60 per cent is covered by sales of 
subscriptions as well as reprints and back issues, he said. 
The meeting of the Committee on Intellectual Property and- Information was 
attended by rep~esentatives of IEEE, the National Science Foundation, the 
American Astronomical Society, as well as AFIPS and others. A representative 
of the Federation of American Societies in Experimental Biology said that the 
scientific community,will not accept the compromise solution. He indicated that 
unless page charges ire mandatory, they "won1 t work. The biology society's 
representative recommended a special exemption from the regulation for scientific 
j ournails . 
The counsel for the National Academy of Sciences agreed that pa e charges cannot 
be voluntary. He said "those who now pay must contlnue [to pay f or serious 
problems [will arise]." He stated that scientific jouqal articles are Itas 
deserving of second-class [mailing privileges] as anything that goes through the 
mail, " 
There was, however, somq support for the USPS compromise. 
One society repre- 
sentative suggested that attendance at the meeting, reflecting opposition to 
the voluntary page charges, was not representative of most professional societies 
views. 
Ancker-Johnson stated that her committee could tlmonitorlf cases brought to its 
attention and act as "brokersv in situations in which voluntary payments, once 
agreed to, werenot made. She confirmed that the compromise is about to be put 
in writing (#I by USPS counsel. 
Ancker-Johnson suggested that further comments concerning the regulation and 
the proposed compromise be directed to her in Room 3862, DOC. 14th Street 
between Constitution Avenue and E Street, N.W. Washington, DCmZO23O; telephone 
is (202) 377-3111. 
NEWS BRIEFS 
$42.9 billion in total funding is predicted for U.S. RBD in calendar year 1977, 
according to the annual RGD forecast of l~attellets Columbus Laboratories. 
Federal Judge Joseph C. Waddy lest month ruled that antitrust laws apply to the 
Bell System; ATGT has argued, since a suit was filed in Washington two 
years ago by the US., that antitrust laws do not apply to the monopoly 
because it is already regulated by the states and the - FCC. 
Liongl Van Deerlin, chairmm of the House Communications Subcommittee, last 
November asked the FCC to expand its- new mlComputer Inquiry" to include an 
examination of the 1956 tonsent decree with A~GT* -* the hec-ree prevents the 
Bell System f~om offering unregulated products or services. 
Sen. ~brahak Ribicoff (D-c~~J, chairman o-f the Senate Committee on Government 
erations, is expected to hold mfcomputer abusem1 hearings this spring [see 
* Was wlgton Report, 7/76) ; Donn 0. Parker of the Stanford Research Institute, 
Men10 Park, California, will testify. 
me Offhe of ~kageqpnt and ~udget (OMB)- last month proposed an CbrdB C$reular 
establishing a' uniform policy for all executive branch agencies in working 
with commercial (i. e. , non-Federal) standards-setting bodies; the proposed 
C.tmZtu, No. A [#) appeared in the Fedem2 R"eg5ster on December 8, 1976, 
p. 53724. 
A proposed standard for Optical Character Recognitign (OCR) Paper (A) is being 
recommended for Federal use by the National Bureau of Standards; the 
standard, which adopts American National Standard X 3.62-197 ----a now 
in the final approval process, provides the requirements and test procedures 
for paper to be used in OCR Systems; it appears in the FedmZ Reg%ster, 
December 9, 1976, pp. 53836-53839. 
The newly established Office of Science and Technology Policy (OSTP) has reportedly 
negotiated contracts with the Futures Group, Inc. and Harbridge,House - for 
studies on how OSTP should fill its legislative mandate; the Office is 
charged with issuing an annual report and five-year forecasts on national 
RGD activities; in addition, two of the three assistant director positions 
have been filled by former National Science Foundation personnel : Philli~ 
Smith is the assistant director for natural resources and commerciai 
semrices, and Dr. Russell C. Drew is the assistant director for national 
security. 
The - FBI has reportedly asked the Department of Justice for permission to abandon 
a nationwide criminal records computer system; Attorpey General Edward H. 
Levi has also asked Congress to consider the major policy implications of 
- 
such a system. 
The Federal Advisory Committee on False Identification has recommended apainst 
a national ID card, accord3ing to an 800-page report on criminal use 
of false identification (I) issued by the =artment of Justice. 
Copies of the October 8, 1976, l+etdminmy Report I% Cimgres8 an6Xe h.ds2ent 
of the National Colamission on New- ~echnological uses of Cop)rrQhted Works 
(CONTU) are now available [I) ; the repert summarizes CONTUfs first-year 
activities. 
A report, titled apsmting Structur,e8 to Support SecuAty d ReZiable Softanre, 
written by Theodore A. Linden, hasbeen issued by the National Bureau of 
Standards (#--enclose $1.251. 
Establishment of a Washington Office for DPMA has been approved by the associa- 
- 
tionms international board of directors; the new Office is being designed to 
coordinate with, as well as supplement the activities of the APIPS Washington 
Officem DMPA's new facility is scheduled to open mid-year. 
I 
The major annual conference of AIAA is being held here January 10-14, 1977. 
LI_ 
INFO/EXPO '77 is being scheduled by DPMA October 9-12 in Washington. 
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AFIPS IN WASHINGTON 
WASHINGTON OFFICE GATHERING DATA TO UPDATE STATB OF THE COMPUTER INDUSTRY 
REPORT 
The Washington Office last month began data gathering to update AFIPS1~e 
Stute Q~Z the Computer IndusAt:ry, edited in 1973 by Dr. Bruce GiZchrist and 
Br. Richard E. Weber. The updated research, which may later be incorporated 
into a report, is focusing on major trends in information processing to 
reflect the breadth, growth, and pezvasiveness of the information processing 
field 
It covers: suppliers, users, and costs; usage and applications; sales; and 
education and employment. Representatives fxom several market research firms 
have indicated a willingness to participate in the study. 
A part-time 
research assistant, William Erickson, has been hired on a temporary basis to 
work on the update with Pender M. McCarter, research associate. 
AFIPS PANEL MEMBERS COMMENT ON USE OF SOCIAL SECURITY NUMBER AT REQUEST OF 
. 
PRIVACY COMMISSION: ADDITIONAL RESPONSES DESCRIBED 
Last month. AFIPS Washington Report described responses of some members of 
an AFIPS panel on private sector usage of the Social Security Number (SSN) 
to a position paper on this subject issued by the Privacy Protection Study 
Commission. We now report several additional responses which have since been 
received from: Jeffrey V. White, president, The Credit Bureau, Inc. (CBI), 
Atlanta, Georgia; John J. Stiqlemeier, director, Information Center on 
Education, New York State Emucation Department; Alden R. Dalzell, director 
of Data Processing, Ohio University, Athens, Ohio; J.M. Moore, section head, 
Exxon Corp., Florham Park, New Jersey; and William E. Perry, director of EDP 
and Research, the Institute of Internal Auditors (IIA), Orlando, Florida. 
Credit Bureau President White wrote: "Since one of CBI's primary obligations 
is to maintain the confidentiality of the informatibn in its data base, we 
would be opposed to any general prohibitions against the use of the Social 
Security Number in the private sector. While CBI does not use this number as 
a universal identifier or as a sole factor in the identification or authenti- 
cation process, it is an aid in maintaining confidentiality in a small number 
of cases. Therefore, eliminating the use of the Social Security Number would 
have an adverse impact on our ability to serve the consumer and the credit 
granting community. 
Bxxon Section Head Moore wrote:  he presence of the SSN in the record 
constitutes unique identification and restricting its use as a formal record 
identifier would serve no useful purpose," Ohio University Data Processing 
Director Dalzell said: "I would question whether the individual's knowledge 
and consent should be s complete qualifier. Ark individual may be informed 
that he need not supply information if he does not wish, and he may be in- 
formed of how it will be used, but that does not completely answer the 
question of whether the information should he gathered and used, even with 
his permission ." 
New York State Education Department Director Stiglemeier wrote that the 
Commission's position paper constituted an "excellentn outline of the project 
boundaries and issues, but the paper's introduction omitted discussion of 
"goals. infomation needs, and inte~relationships with other pro j ects . He 
called these omissions "criticalv1 to the success of the project. 
IIA EDP/Research Director Perry cited example's of what he called vlsome 
preconceived findings and conclusion sf^ of theposition paper, described by the 
Commission as av@oblem and issue ~tatement.~~ He mentioned such Commission 
flfindingss" as "the use of the SSN for personal authentication does not appear 
in itself to constitute an unfair information practice," and Ifthe exchange of 
information without the knowledge or consent of an individual may constitute 
an unfair information practice.ll Perry also wrote that individuals who feel 
that divulging the SSN for personal authentication is dehumanizing "would 
probably object to the alternatives even moreaVr 
The kF1PS Washington Report is researched and written by ~Gnder hi. McCarter, 
- 
Research Associate, AFIPS Washington Office. 
AFIPS societies have permission 
to tlse material in the AFPS WaehCngton Report for their own publications, 
except where an article title appears with an "(*)," clearance must first be 
obtained from the AFIPS Wa~hington Office. 
Documents indicated by the symbol 
it(#)tr are available on request to the AFIPS Washington Office. 
Where price is 
noted, make checks payable to tlAFIPS.tl 
- 

References 
[I] Colby, K.M., Parkison, R.C., and Faught, 8. Pattern-Matching 
Rules for the Recognition of Natural Language Dialogue 
Expre~sions. A1 Memo 234, St~nf0r-d Artificial Intelliqence 
Laboratory, Stanford University, June 1974. 

[2] Davis, R., and King, J. An Overview of Production Svstems. 
To appear as Machine Representations of Knowledge published 
as Machine Intelligence 8 (eds. E.W. Elcock and Dm Michie), 
John Wylie, December 1976. Also available as A1 Memo 271, 
Stanford Artificial Intelligence Laboratory, Stanford 
University, October 1975. 

131 Davis, R., Suchanan, B. G., and Shortlif fe, E . H. Production 
Rules as an Approach to Knowledqe-Based Consultation Systems. 
A1 Memo 266, Stanford Artificial Intelligence Laboratory, 
Stanford University, October 1975. Also accepted for 
publicat ion in Artificial Intelligence, Februarv 1977, 

[4] Davis, R. Applications of Meta Level Knowledge to the 
Construct ion, Maintenance and Use of Large Knowledqe 
Bases. Doctoral dissertation, Stanford University, 
June 1976. Also available as A1 Memo 283, Stanford 
Artificial Intellieence Laboratory, Stanford 
University, July 1976. 

151 Shortliffe, E.H., Axline, S.G., Buchanan, R.G., Merigan, T.C., 
Cohen, S.N. An Artificial Intelliqence Program 
to Advise Physicians Regarding Antimicrobial Therapy, 
Computers and Biomedical Research. 6,544-560, 1973. 

C61 Shortliffe, E.H., Davis, R., Buchanan, B.G., Axline, S.G., 
Green, C. C., Cohen, S .N. Computer-Based Consultations in 
Clinical Therapeutics: Explanation and Rule-acquisit ion 
Capabilities of the MYCIN System. Computers and Biomedical 
Research 8,303-320, 1975. 

171 Shortliffe, E.H. MYCIN: A Rule-Based Computer Proqram to 
Advise Physicians Regardinq Antimicrobial Therapy Selection. 
Doctoral dissertation, Stanford University, October 1974. Also 
available as Com~uter-Based Medical Consultations: MYCIN, 
American Elsevier, 1976. 

[83 Winoqrad, T. Undersanding Naural Lanquaqe. Coqnit ive 
Psycholosy 3,)-191, 1972. 
