Interactive Discourse: Influence of the Social Context 
Panel Chair's Introduction 
Jerry R. Hobbs 
SRI International 
Progress on natural language interfaces can perhaps be 
stimulated or directed by imagining the ideal natural 
language system of the future. What features (or even 
design philosophies) should such a system have in order 
to become an integral part of our work environments? 
What scaled-down versions of these features might be 
possible in the near future in "simple service systems" 
\[2\]? These issues can be broken down into the following 
four questions: 
i. What are the significant features of the environment 
in which the system will reside? The system will be one 
participant in an intricate information network, depend- 
ing on a continually reinforced shared complex of knowl- 
edge \[9\]. To be an integral part of this environment, 
the system must possess some of the shared knowledge and 
perhaps must participate in its reinforcement, e.g. via 
explanations, \[9\], \[2\]. 
2. Investigations of person-person communication sho111d 
tell us what person-system communication ought to be 
like. Face-to-face conversation is extraordinarily rich 
in the information that is conveyed by various means, 
such as gesture, body position, gaze direction \[4\], \[8\]. 
In addition to conveying propositional content or infor- 
mstion, what are the principal functions that moves in 
conversation perform? 
a. Organization of the interaction, regulation of turns 
\[7\], \[i\]. In the natural language dialog systems of 
today, each turn consists of a sentence or less. In ex- 
periments done at SRI on instruction dialogs between 
people over computer terminals, the instructor's turns 
usually involve long texts. It was discovered that the 
student needs a way of interrupting. That is, some sort 
of turn-taking mechanisms are required, what can we 
learn from the turn-taking mechanisms people use? 
b. Orientation of the participants toward each other, 
including recognition \[6\], expressions of solidarity and 
indications of agreement and disagreement \[3\], meta- 
comments on the direction of the conversation \[8\] or the 
reasons for certain utterances (\[9\] on discourse expla- 
nations). 
c. Maintenance of the channel of cO~unication, implic- 
it acknowledgment or verification of information con- 
veyed \[2\]. Recovery from mistakes and breakdowns in 
commtunication \[8\], e.g. via flexibility in parsing and 
interpretation \[2\]; via explicit indications of in- 
comprehension \[2\] and repairs \[5\]. In natural language 
systems of today, when the user makes a mistake and the 
system fails to interpret the input, the user must usu- 
ally begin over again. The system cannot use whatever 
it did get from the mistake to aid in the interpretation 
of the repair. People are more efficient, what are the 
principal means of repair that people use, and how can 
they be carried over to natural language systems? 
taining one's role, e.g. as a competent, cooperative 
participant (cf. \[8\]; \[9\]; \[i\] for the role of speech 
style; \[4\] for defense of competence). In addition to 
the system having a model of the user, the user will 
have a model of the system, determined by the nature of 
his interaction with it. The system should thus be 
tailored to convey an accurate image of what the system 
can do. For example, superficial politeness or fluency 
("Good morning, Jerry. What can I do for you today?") 
is more likely to mislead the user about the system's 
capabilities than to ease the interaction. What the 
system does, via lexical choice, indirect speech acts, 
polite forms, etc., to maintain its role in the inter- 
action should arise out of a coherent view of what the 
role is. The linguistic competence of the system is an 
important element of the image it conveys to the user 
\[2\]. 
3. When we move from face-to-face conversations to 
dialogs over computer terminals, the communication is 
purely verbal. The work done non-verbally now has to be 
realized verbally. How are the realizations of the 
above functions altered over the change of channels 
\[6\]? We know, for example, that there are more utter- 
ances showing solidarity and asking for opinions, 
because this is work done non-verbally face-to-face \[3\]. 
Some things that occur face-to-face (e.g. tension 
release, jokes) seem to be expendable over computer 
terminals, where each utterance costs the speaker more. 
The messages take longer to produce, are less transi- 
tory, and can be absorbed more carefully, so there is 
less asking for orientation, elaboration, and correction 
\[3\]. What devices are likely to be borrowed from 
related but more familiar communication frames \[i\]? 
Possible frames are letters or telephone conversations. 
4. Should and how can these functions be incorporated 
into the ideal natural language systems of the far 
future and the simple service systems of the near 
future \[2\], \[8\]? 
REFERENCES 
I. Carey, 3. Interactive television: A frame analysis. 
From M. MOSS (ed.), Two-WayCable Television: An 
Evaluation of community Uses in Reading, Pennsylvania. 
Final report to the National Science Foundation. 1978. 
2. Hayes, P. and R. Reddy. An anatomy of graceful 
interaction in spoken and written man-machine conununica- 
tion. Computer Science Department, Carnegie-Mellon 
University. 1979. 
3. Hiltz, S. R., K. Johnson, C. Aronovitch, and M. 
Turoff. Face to face vs. computerized conferences: 
A controlled experiment. Draft final report for grant 
with Division of Mathematical and Computer Sciences, 
National Science Foundation. 1980. 
d. Building and reinforcing the mutual knowledge base, 
i.e. the knowledge the participants share and know they 
share, etc. \[9\]. Linking new or out-of-the-ordinary 
information to snared knowledge via explanations \[9\], 
\[2\]. 
e. Inferring others' goals, knowledge, abilities, focus 
of attention \[8\], \[2\], \[4\]. The system should have a 
model of the user and of the cormnunication situation 
\[8\]. 
f. ConTaunicating one's own goals, knowledge, abilities, 
focus of attention \[8\], \[2\]. Establishing and main- 
4. Hobbs, J. and D. Evans. Conversation as planned 
behavior. Technical Note 203. SRI International. 1979. 
5. Sacks, H., E. Schegloff and G. Jefferson. A simplest 
systematics for the organization of turn-taking for 
conversation. Language, Vol. 50, no. 2, 696-735. 1974. 
6. Schegloff, E., G. Jefferson and H. Sacks. The 
preference for self-correction in the organization of 
repair in conversation. Language, vol. 53, no. 2, 
361-382. 1977. 
7. Schegloff, E. Identification and recognition in 
65 
telephone COnversation openings. In G° Psa~has (ed.), 
Everyday Language: Studies in EthnometbodoloqY. 23-78. 
8. Thomas, J. A design-interpreuation analysis of 
natural English with applications to man-computer inter- 
action. International Journal of Man-Machine Studies, 
Vol. I0, 651-668. 1978. 
9. Wynn, E. Office conversation as an informauion 
medium. Ph.D. Thesis, Department of Anthropology, 
University of California, Berkeley. 1979. 
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