SYNTACTIC PRIVILEGE 
Michael B. Kao 
Dept. of Linguistics, University of~esota, Einneapolis, 
Minnesota 55455 USA 
This paper is addressed to the view of Schank and Birn- 
baum (1981) that syntax has no "privileged'position in pars- 
ing. Evidently what is meant is (a) that syntactic parsing 
has no logical or temporal priority over semantic processing, 
and (b)that syntax has been as@igned attention far out of 
proportion to its interest or distinctiveness. (The latter is 
not asserted outright, but seems implicit in the overall tone 
of the discussion.) In the view of the authors (henceforth 
"SB'), syntactic considerations come into play in sentence 
u~derstandi~E only where it is needed to resolve indeterminac- 
ies. It is this view that I wish to subject to scrutiny. 
Part of the case for the position that syntacting pars- 
ing is not a prerequisite to semantic analysis lies ix~ the 
fact that there are sentences which can be understood without 
a~y invocation of syntactic considerations at all. Such a 
case is 
( 1 ) John ate lunch. 
since it is intrinsic to the concept of eating that it is an 
action carried out by animate beings; thus, since only J=o~_~ 
denotes such a being in (I), it denotes the actor, leaving 
lunch to be understood as denoting whatever was ingested. On 
the other hand, since animate beings are themselves i~gestib- 
le, one would presumably have to invoke at least low-level 
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syntactic cues to correctly parse 
(2) The oanmibals ate the Rev. Dr. Abercrombie. 
It is possible, however, that SB would deny that syntax must 
be called even in this case since world knowledge might be 
capable of sorting out the roles. One might suppose that there 
is a script called ,~CANNI3AL which includes a soeDario in- 
volvi~E putting missionaries in pots of boiling water and 
then eating them; assumil~ that there is no other world know- 
ledge to suF~eet that missionaries typically return the favor, 
then (2) can be parsed asyntaotically as well. If this is so, 
however, then there is a problem with 
(3) The Rev. Dr. Abercombie ate the cannibals. 
No speaker of ED~lish would interpret (3) as synonymous with 
(2); thus, even if (2) is parsed asyntactically, (3) could 
not be. But given that the amount of prior semantic informat- 
ion (i.e. individual word meanings) is exactly the same in 
both cases, how is a decision to be made to call the syntax 
in the case of (3) but not in the case of (2)? Comparable 
problems will frequently a~ise with figurative language; so, 
for example, 
(4) The tail wagged the dog. 
is a way of saying that some expected relationship was revers- 
ed; and yet ~ is a good case of an asy~etrio predicate, 
requiring that one of its arguments refer to a body part or 
extension thereof (such as a flag) while the other denote an 
animate being of some kind. In a case like (4), there is no 
indeterminacy on purely semantic grounds as to which NP should 
denote which, but the result that would ensue from processing 
(4) in parallel fashion to 
(5) The dog wagged his tail. 
is, in effect, overruled by the syntax. It is, indeed, only 
from this overruling that one would know that one was dealing 
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with figurative language. Assuming that (4) is parsed srsntac- 
tioall7 but not (5), we are then forced onto the following 
dilemma: syntax is called only where it is needed to overrule 
the consequences of an asTntactic pa~se; but the conditions 
under wh£ch such a call need be made themselves depend on sTn- 
taottc~ information (in this case word order cues), since the 
word-level semantic information (all else that is available) 
cannot distinguish (4) from (5). 
What SB have done here:: is to confuse redundancy and 
superfluity. Cases like (1) and (5) show that syntax is some- 
times redundant; but since word-level semsnti~ does not pro- 
vide a way of distJ~l&~Lshi~ when it must be called and when 
it need not be, syntax must be called indisorimJ~tel~. We 
might call this the "fail-safe" conception of the interaction 
of syntax and semantics. 
Nonetheless, SB might well answer, there is evidence 
that human language users actually do parse asyntaotically. 
They cite the fact that someone with imperfect knowledge of a 
foreign language may nonetheless be able to read written ma- 
terials in the language, using nothi~ but word meaning and 
world knowledge as a guide. But while there is no doubt that 
human beings are capable of doing this, it does not follow 
that this is what they would do if they were not forced to° To 
say that one often doesn't need a certain kind of knowledge to 
CaZT7 OUt a given task does not imply that one ignores it tf 
one has it. 
I would like finall7 to call attention to a problem that 
is not addressed at all by SB, but which is at the very center 
of concern in the design of adequate natural language under- 
standing systems° As SB present it, the problem of language 
understanding comes down to that of ascertalnlng the meanings 
of 11~u/stio expressions and then interrelatlng them in appro- 
priate w~.Ts. No mention is made, however, of the problem of 
knowlng what the expressions are to begin with. How does one 
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know, for example, that Kreen aDDle is an expression denoting 
the object of perception in (6a) but not in (6b)? 
(6) a. John saw the ~reen apple. 
b. John saw the green apple tree. 
Examples of this kind can be multiplied in many dlrections. 
Pot example, in 
(7) a. I watched John and Mary run to the police station. 
b. I watched John and Mary ran to the police station. 
John and Mar~ is an expression denoting the performers of the 
act of running in (7a), but not in (To), The kinds of examples 
discussed by 3B involve few multi-word constituents, and those 
that do arise seem to be of a kind that can be handled by rath- 
er local recognition meohanis~s; but cases like (7) show the 
need in some cases to take global syntactic context into 
account as well. The problems that arise in this regard are 
not trivial, and as long as they exist, syntax will remain 
"Privileged" at least in the sense that it will make a major 
claim on the attention of some investigators and thus conti- 
nue tO have a life of its own. 
References

Schank, R. and L. Blrnbaum, 1981. Mesz~ng, Memory and Syntax. 
Dept. of Computer Science, Yale University. Res. Rep. 
No. 189. To appear in T. Bever and L. Miller, eds., 
Cog~itlve Philosophical Computational Poundatlone of 
Language. In press. 
