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What is in the frame? — Linguistic indicators
Journal of’hagmatics 5 (191Bl) 35-44 @Nort&HoRland Publishing Company
IIS IiN THE FRAI
C INDICATORS
sp+ciaB ;agc:sof t;le definite article and of negation a,re discussed in the light of Minsky’s concept of “thef?Qme. On the one hand, the latter concept is amployed in order to explain the unconventional usage:;, on the other hand the linguistic phenomena are taken as indicdrtars to what is in the frame.
The problem of representation is considered by many as the central res.:arch issue in artificial intelligence today. This appraisal steamsfrom the understanding th-at for any infomration processing system to be engaged in complex manipulatL3n of concepts, it has to have a usable seman& representation. The task of the cognitive scient.M - be he interested in natural or artificial intelligence - is to discover the principles by which such representations are defined. In recent years, various representational formats halie been proposed as possilble czriers of everyday knolwledge. These include fi~mes (originally pro1 osed in Minsky 1975; for furthcx developments see Winograd 1975 4 and Char liak 1977), scripts (originally proposed in Schank et al. 1975; for further develo.?ments, includiig other types cf representatier., see Schank and Abelson 1977;., 1977b)!, schemzta (Bobrow and Norman 19;“5)1and descriptions (Bobrow anld Winograd. 1977). While there are technical proposed, in essence they dif ferlences betxeen the various types of representa JI(offer share many features all addrest; the same basic problem and the solutions in common. Specifically, any representation of common-sense knowledge has to list the q,pical characteristics of the situations, agents, or objects in quesr:ion, but it the information Y&.U pertains to these entities. Hence, a selectiori cannot di:tail be employed in orde;, TV’decide what to include in this representa s procedure has what not to include in 3t. 43~way of dealing with this problem, most include not ordy descriptions of particulars but also guiding representzrtions * I thank I M. Schletiger for his helpful cocl Inents. Author s address: Dept. of Psychobgy, l’%e Hebrew University of Jerusalem, Jerusalem, Israel. [ 11 As originaly proposed, the script, SC:4~gfixed and “predetermined” does not abide by this c’tuuacterization, but the more recent ;vork conducted at the Yale 4.1. Project (Schank and Abelson 1!177a, B’$7+Yb) does. 35
63,.Sharon / Linguistic indicators
36
lines for what to observe, look for and check. Minsky’s characterization of’ the frame is representative of this line of thinking. A “‘Frame”, Mimky (1975) says, “‘is a data structure for representing a stereotyped situation, like being in a ca!.rtainkind of living room, or going to a child’s bdrthday party. Attached to each frame are several kinds of information. Some of the information is about how to use the frame. Some is about what one can expect to happen next. Some is (about what to do if these expectations are not confirmed”. Differently put,“A frame 1s a collection of questions to be asked about a hypothetical situation: it specifies issues to be raised and methods to be used in dealing with them”. In other words, ths: frame can be viewed as an organized matrbr of slots for &en states of affairs, assigned with specific terminal values on the basis of the particu?ar state of affairs&to which the frame is applied. However, claims l%nsky, “I cQqjecture that frames are never stored in long-term memory with unassigned terminal values. Instead, what really happens is that frames are stored with wea.kJy-bound default assignments at every terminal”. The concept of the frame has gained great popularity, but it has also raised much criticism. It has been noted that it is abstract, genera and non-committal (Drescher and Hornstein 1976; see also Winogr Id 1977). Indeed, it is not clear how frames can be upheld or refuted by observation and testing. In particular, no criteria have ever been given for deciding whether a given piece of information be exgllcitly specified in the frame - or, for that matter, in any other representation - or not. In the present note I try to point out a locus in which !;uch a criterion is, in fact, found. Specifically, I discuss two fa.milies of linguis?ic phcziomena: the definite article and negation. On the one hand, these phenomena seem to blf easily explicated within a framework taking into account semantic representaticjs;s !.ike the ones noted above; on the other hand, these linguistic phenomena might serve as independent indicators for deciding what to include in the representation. Given the great similarity between the different constru.:ts oroposed in the literature, md in l@ht of the great influence exercised by frames, will make aLl future reference to this last construct. The arguments made here, however,, are general and their relevance need not be confined to the Minskyan frame proper [2]. Let us, then, start with the defmite article. The environments in which the definite article is -usedmay be charar;ierized as follows: ) (a) The item introduced by the article is specific. (b) The item introduced by the article has already been mentioned in the conversation or it may be otherwise \?etermined by the context in qutl:stion.. [21 irs demonsrrative of this similarity, let me quote Charnlak’s (1977) defiI1itionof the frame - “A large body of information,expressedin a computer usableformalism&out a single topic where the facts are richly interconnected and which, while typically consulted as a whole consists of basic units (facts) which are ir~dividually used” - and. note that actu;:ll!ly it is a fair
characterizationof the script.
B. Shanon / Linguistic indicators
37
(c) If the item introduced by th_e zrtizle is unique, (b)Iis relaxed [3] . Basically, (*) states that the deGnite article rnaj be used only when determination of reference is possible. In other words, there should be a possibility for the establishment of a link between the item introduced by the def;Wte article and another item which serves as an anchor to it. Condition (a) specifies a prerequisite for this possibility, whereas condition (b) states that the link established may be either lin/@tic (a previous verbal instantiation) or a non-verbal, environmental one (e.g. ostension, in which the anchor is the very object to which one refers). Finally, condition (c) points out that when the -Aass denoted by the item introduced by the definite article is a singleton, no problem regarding LeterminAion cf reference obtains even when r:?oexplicit referential Sink is establis3ed. The conditions stated in (*> are demonstrated by the foilowing senl,ences: (1) Most people haven’t heard of the General Theory of Relativity. (2) The girl John dated is my neighbor’s friend. (3) Don’t touch the wire! In (1) the definite article is used with one item which is unique and well-defmcd. As a consequence, (c) applies, and the anchors specified in (b) are not required. In contrast, the two other sentences demonstrate that links to anchors are required wh.en the class is not a singleton. Sentence (2) exemplifies a linguistic I&-&:unless John dated only one girl the sentence cannot be well-defined when there is no prc rious mention. Sentence (3) illustrates a non-verbal link: the wire may not have been r,rentioned before the utterance at hand, :.U the use of the defmite article is appropriate . Our diszussiori will a‘ocuson several csses which seem to violate (*). As a first case consideir : (4) Pierre se lave les mains. This sentence has a coreferential reading 141. Its Engl 1 rendcdw, may be read either coreferentially or not:
W,
however,
(5) Pierre l&rashes: & hands.
[3] In nl’l’ering (IF) as a charucterization for the use of the definite ar?ls!e ! am Lcusing on types of environments which Go..--* the &finite article to ‘be used. Irrelevant to this discussion are some J,P the philosophical problems commonly associated with the definite arrlcle: the ontology of references, different modes of reading, generic usages and the like. [ 4 ] 1:us’ the terrn “coreferentiality” in a broad sense. Strictly speaking “hands” is not coreferential wi:lI “Pierre”, but the possessor of hands is. This use of term sho\*ld be clear from the context and CloYed not affect xhe reading.
B, Shanon / Linguistic indicators
38
The literal translation of (4), (61, is ungrammatical, a:nd th.at of (S), 1[7), is not coreferen tial : (6) * Pierre washes the ha&. (7) Pierre lave ses mains. The French examples are somewhat deficient in that they are confolrnded with the appearance of the reflexive pronouns se in the sentences with corefet*ential reading., and its absence in the sentences with noncoreferential one. This confounding, how.. ever, is iess significant than it may appear. The I-Iebrew translations of tire FrenchL sentences, for example, are free from it. In particular, in Hebrew one uses the identical verb in both coreferential and non-coreferential readirsgs, Thus, the Mebrew version of (4) Is (6), and that of (7) is (9). (8) Pierre rochetz et ha-yadayim. Pierre washes obj. the-hands. (9) Pierre rokhetz et yadav, Pierre washes obj. hands-his. For the sake of easier reference, the following discussion is based on the French examples. Sentence (4) is interesting because even though here are many hands (i.e. the item introtluced by the definite article is not specific:l, and dtispite the lack of previous mention or particular contextual identification, it is well-de!lned. In other words, even though (*) is not met, (4) is an appropriate sentence. lndeud, it poses no difficulty even in the artifical isolated context in which it appears irere. E~luitively, the interpretation of the sentence is based o:n the following rationale. Usually, people wash their own hands, hence “‘hands” in the given sentexlces is naturally associated with “Pierre’“, the washer. To put it in other words, mani~rw!atingobjects (and in particular, body parts) which beiong to oneself is the usual, unmarked case; as a consequence no explicit indication of possession is required. This rationale may be regarded as an instantiation of the Cricean maxim of quantity (CZce 1975). It is as if the specification of the possessive pronoun is considered by *r.helanguage as more “expensive”, than that of the definite article. Hence, in the unmarked case the article, and not the pronoun, is used. It is significant that the iraterpretation is based on pragmatic grounds, and not on purely semantic ones. i:ir other words, co-reference as such is not sufficient for the employment of the “cheaper” linguistic device. This is demonstrated by the fact that the use of the definite article in (10) does not imply that the book is John’s: (10) John re,ads the boo.k.
B. Shmon / Linguistic indicators
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A.3hinted above, the phenomenon noted here is not limited to body parts, but obtains whenever the particular referent is considered “most natural”, ;znd as such does not require furthe], specification even when no explicit anchor it; provided. Sentence (1 I) is an example of a use of the definite article with an unmarked referent other than a body part: (11) II est all6 a la maison. He went to. the house. He wl;nt home. A second case not covered by (*) is exemplified by (I 2) and (13): (12)1John cirne to Mary’s birthday, but forgot ‘.obring the present with him. (13) When l’om flew for the firs: time, he was \.ery eager to meet the stewardess. The sentl:nces differ from sentences (4) and (7) in that their analysis is not corlfind t;~ the reaIm of language proper (as exemplified by the Gricean maxims) but involves :he consideration of more g:neral cognitive structures. In par titular, the use of the definite article in these sentences is not tied to a particular semantic phenomenon such as the determinatitiir of possession relations, but bears on the speaker’s kncwledge of the world. Sentences (12) and (13) are not unmarked cases which correspond to more informative marked ones, yet, given the situation, the special identiry of both present and stewardess is clear. The present is the one John boug!rt for Mary, the stewardess is one attending Tom’s plane. There is nothing “usual” or “unmarked” about the!:e particular assignments, moreover they need not be unique (i.e. there could be mo:e than one stewardess on the plane). Yet, these cases pose no problems of interp:etatior,. When one goes to a birthday party one btigs a present. Hence the present is the one one bought and is supposed to bring, A similar argument holds for the stewardess and the plane. These ideas bring us back to Minsky’s Frames ecifidy, if the item introduced by the definite article appears as a terminal v in the relevant frame, and if its default value is implied, no explicit specificati an IanchDr is needed Thus, Charniak (1972) we note that the birthday frame includes, among other things, PRESENT as a terminal value. Givl:n. that this item is actu&/ specified in the frame, sentence (12) is fully understood even when uttered in isolation. The definite article is used even though herVe are many presents in the world, and no previous mentioning was noted. Sentence (13) is accounted for in a similar fashion. The case exemplified by (4) r-nay be analyzed on similar lines as well: “one’s own” is lhe default value for possession relations. This assignment, however, unlike that noted in (12) and (13), is very general, and imphes no particular Frame The t\vo cases introduced here as violations of (*) may, indeed, be viewed not as counter-examples to this characterization, but rather as ones that extend it. They demonst;.ate that in addition to verbal and contextual anchors there are also prag
Rather than linking the item introduced by the definite article to another verbal description or an actual referent, the speaker may link it ‘to a conceptual representation a.ssumed to be shared by the members of the given com-
maticcognitive
ones.
munity .
Following are PJrther usages of the defmite article which are not covered by (*) but which may be explicated in the manner just suggested. Question (14) and the answer to it (15) were collected in an, empirical survey in which pnswers to questions were investigated; the conversation actually took place in a restaurant setting
. Fl .
(14) Why did you read the menu? (15) I read the menu because the waiter gave me one. The exchange is interesting because (15) may be appropriate even when more than one waiter is present in the restaurant in question. Specifically, it offers a case where the very first prerequisite of (*) is violated: the item introduced by the defiiite article is not specific yet determination of reference poI;es no probiem. That this is, indeed, the case is further demonstrateId by the fact that (16) is not an appropriate reaction to (15). (16) Which (with rising intonation) waiter? This is unlike (18), which would have been an appropriate reactiorl to (17), ha.d it, (17), been given as an answer to the original question (14): (17) Because the pilot gavs me one. (18) Which (with rising imonation) pilot? The foregoing examples suggest tha: +Lhecognitive link may nut be subject to condition (a) of (*). The Frame offers an anch.or (in our case, WAITER) which is weh-defmed even though the object in the real world which corresponds to it is not a single, specific one. The phenomenon just considered is particularly noted when function rather than specific reference is of interest. Thus, consider sentence (19) when uttered at a dinner table on which there are two salt-shakers: (19) Would you pass the salt-shaker please? The use of the defmi?e article is perfectly appropriate even t ough ithe item it intro15 1 Restaurants - amongst other settings - were chosen in obtious reference to Schank’s work. The analysis of the entue corpus of answers is tht: focus of research which is now in progress.
B. Shanon / Linguisd?c indicators
41
duces is not unique, no previous mention need have been made to it, and the speaker need not accompany his request with a gesture. None of tie conditions of (*) is observed, yet the responder will have no difficulty in handing over one of the salt-shakers. (19) is appropriate because what is at stake is the est rblishment of a link t,o the “salt” as presented in the relevant frame; the choice of 1:particular saltshaker as its value, however, is immaterial. A similar use is found in corn non functional expressions: (20) (21) (22) (23)I
He went to the post office. She went to the grocery store. They went to the laundry. Yesterday, I went to the delltist.
Note that in these sentences tht action denoted by the verb is not taken literally, but rather as a place holder for a routine deduced from the meaning of the object that follows. Going to the grocery store, for example, is not equivalent to walking or driving from one’s home to thi: grocery store. So far I have referred to the notion of the Frame in order to explicate various seemingly deviant usages of the definite article. The opposite course, however, is possible as well. In other words, the usages in question may be !aken as indicators marking the identity rjlt the values spec:Xied in the Frame. Specifically, if an item is intro&iced by the definite article in a way which violates (*), one can conclude that item is specifically stored in the cognitive Frame [6]. While the main topic of the present paper is the definite article, I would still like to make some additional comments regarding another linguistic construct, negation. The comments made regarding negation are not as developed as the ones having to do witit the defmite article, but they lead to identical conclusions with respect to the relationship between language and conceptual representation. Thus, consider another verbal exchange collected in the survey mentioned above. The exchange took phce in a university cafeteria: (24) Why did you pick the food by yourself? (25) Because I saw that there was no waiter. Sentencs (24) is rather curi:Dus: one sees that things are, but how can one see that =-jple By wiay of analyzing this e,., _.__ let me make a short digression. Even though affirmative and negative sentences are completely symmetric from a logical point of view, pragmatically they are very different. People describe the world as it is, rather
[6] For further discussions of the definite article in the artificial intelligence ‘kiterhture,set Schanlc and Abelson (1977a).
42
B. Shanon / Lirtguistic indicators
than according to what it is not. Thus, even though both refer to an identical state of affairs in the re&!world, pragmatically (26) and (27) are different: it is natural to use (26), but not (27): (26) H is in the room, (27) A, a.., G, I, .. . Z are not in the room. Evidently, one may, and one does, employ negation. However, the “pragmatic value” of affirmative and negative sentences is not the same. In uttering an affirmative sentence a speaker commits himself only to the truth of the statement he makes. In contrast, in utt&ng a negative statement a speaker not only states that a certain state of affairs does not hold but that l!l\ere is something special about the fact that it doesn’t. The higher value is :jssociaied with a higher price: a speaker would not utter a negative statement unless he has sp+:ci,llreason to do so. In our case, (27) cannot be uttered unless A, .... G, I, ... Z have disappeared, are expected, or are supposed to be present; no similar assumptions ne2d to be made in conjunctinn CIV.. with ..*.a. (361 \W’,.
Returning to (24)---(X) we conclude that answer (25) could not have been given unless the presence of ‘“waiter” was assumed somewhere. This alleged place, however, is not provided in the context nor does it seem to be particular to the speaker’s experience, 3s would have been the case with (26). Rather, the normalcy c--f(25) may be attributftd to the presence of the negated object in a mental frame, a Minskyan Frame, which is relatively independent of the r:xperiences of the p:rrticular speaker and is sh;ired by the members of the cognitive community. The Restaurant frame, as we noted, contains WAITE:Ras one o i its values. The fact that (28) is not a normal answer to (24) indicates that PLANE iz not in that frame: (28j Because I saw that there was no airplane th:re. It should be emphasized that the reason expressed by (28) might have indeed been the one underlying the speaker’s behavior. Yet it would ncbt have been appropriate for him to give it as a justification without an additional ‘“story’“.The waiving of this requirement, we would say, is indicative of the nega:.ed entity “being in the Frame”. Other special usages of negation were found in an empirical survey of how people describe rooms. As expected, practically all the sentences in t:re descriptions were affirmative. In a corpus of more than 20@sentences, however, two cases were encountered in which the negative mode was en ployed: (29) We don’t have any furniture. (30) The ceiling is without a lamp. Neither “furniture” nor “‘lamp” were mentioned earlier in the description. Just in
B. Shanon / Linguistic kdicators
43
order to emphasize the special status of (29) and (30) note the great peculiarity of Etatements such as (3 1) or (32): (3 1) We don’t have any diamonds in the room. (32) The ceiling is without carpeting. The explication of these facts should, by now, be obvious. “Furniture” is specified in the Room Frame, but “diamonds” is not. Similarly, “lamp” is specified in the ceiling sub-Frame, but “carpeting” is not. To conclude, the construcions discussed here may be considered from a common perspective. These conslructions require an antecedent reference point. In ordinary phrases this point is established either explicitly in the linguistic structure itself or implicitly on pragmatic grounds, including non-verbal communication, assumed shared knowledge of’ the speaker-hearer and common expectations. The examples noted here did not belong to either of the two type*. It was suggested that they constitute examples of a third type in which reference is made to cognitivV1* litp Mirr~t~l’n C*r~nid~l :,-C-m-,- -_a =*:-.-.-.Jr--&a.‘#ctnlf)llr~f “L*U”C”a”” llzI”*.Ulr*RJ 3& lQdlIG3. 1Cm~r+har UIUIGI,*XPLA~ WlICll+Ir~-n LiIC3C IIIJltlllc;CJ a1c vlc"wcu llUlll another perspective, they may be taken as indicators to “What is in the Frame”.
eferences Bobrow, D.G. and D.A. Norman. 1975. ‘Some principles oi memory schemata’. In: D.G. Bobrow and A. Collins, eds., Representation and understan iing. New York: Academic Press. pp. 131-150. Bobrow, D.G. and T. Winograd. 1977. An overview of KRL, a knowledge representation language. Cognitive Science 1: l-46. Charniak, E. 1972. Toward a model of childrefl’s story comprehension. M.I.T. Artificial Intelligence Laboratory. Charniak, E. 1977. A framed painting: the representation of ;t conlmon ti,-nse knowbdge payment. Cognitive Science 1: 355-394. Dresher, E. and N. IIornstein. i976. On some supposed contrihlr p~on9of artificial intell’igence to the scientific study of language. Cognition 4: 321-398. Crice, H.P. 1975. ‘Logic and conversation’. In: P. Cole and J.L. Morgan, eds., Syntax and semantics, 3. New YorT.: Academic Press. pp. 4 l-58. Iv’inqky, M. 1975. ‘A frac .ework for relzresenting knowledge’. In: P.H Winston, ed., l%e psychology of computer vision. New York: McGraw-Hill. pp. 2 1 l- 27 ;’( Sc,jank, R.C. and R. Abelson. 1977a. Scripts, plans, goals and understanding. New York: Halsted. Schank, R.C. and R. Abelson. 1977b ‘Scripts, plans and knowledge’. ln: P.N. Johnson-Laird and P.C. Watson, eds., Thinking: readings in cognitive science. Cambridge: Cambriage University Press. pp. 42 l-432. Schank, R.C. and the Yale Artificial Intelligence Project. 975. SAM - a story understander. Yale University computer science research report 43. Winograd, T. 19’75. ‘Frame representation and t’he declarative-procedural controversy’.In: D.G. Bob:ow and A. Collins, eds., Representation and understanding. New York: Academic Press. pp. 185-210.
Winograd, ‘T’.1977. On some cantested suppositions study of language. Cognition 5: 15 I- 1.79. Benny Sh.anon,
ofgenerative linguistics about the scientific
born 19 8, studied philosophy and linguistics as an undergraduate at Tel Aviv University and obtained an M.A. in linguistics ainda Ph.D. in psychology at Stanford. Taught at M.I.T. Ynd is presently at the Department of Psychology of the Hebrew University. interested in the indastigation of semantic prablems from several different perspectives: the cognitive experimel;tal, the theoretical linguistic, the neuropsycholegical and that of cognitive science and artit’tcialintelligence.
IIS IiN THE FRAI
C INDICATORS
sp+ciaB ;agc:sof t;le definite article and of negation a,re discussed in the light of Minsky’s concept of “thef?Qme. On the one hand, the latter concept is amployed in order to explain the unconventional usage:;, on the other hand the linguistic phenomena are taken as indicdrtars to what is in the frame.
The problem of representation is considered by many as the central res.:arch issue in artificial intelligence today. This appraisal steamsfrom the understanding th-at for any infomration processing system to be engaged in complex manipulatL3n of concepts, it has to have a usable seman& representation. The task of the cognitive scient.M - be he interested in natural or artificial intelligence - is to discover the principles by which such representations are defined. In recent years, various representational formats halie been proposed as possilble czriers of everyday knolwledge. These include fi~mes (originally pro1 osed in Minsky 1975; for furthcx developments see Winograd 1975 4 and Char liak 1977), scripts (originally proposed in Schank et al. 1975; for further develo.?ments, includiig other types cf representatier., see Schank and Abelson 1977;., 1977b)!, schemzta (Bobrow and Norman 19;“5)1and descriptions (Bobrow anld Winograd. 1977). While there are technical proposed, in essence they dif ferlences betxeen the various types of representa JI(offer share many features all addrest; the same basic problem and the solutions in common. Specifically, any representation of common-sense knowledge has to list the q,pical characteristics of the situations, agents, or objects in quesr:ion, but it the information Y&.U pertains to these entities. Hence, a selectiori cannot di:tail be employed in orde;, TV’decide what to include in this representa s procedure has what not to include in 3t. 43~way of dealing with this problem, most include not ordy descriptions of particulars but also guiding representzrtions * I thank I M. Schletiger for his helpful cocl Inents. Author s address: Dept. of Psychobgy, l’%e Hebrew University of Jerusalem, Jerusalem, Israel. [ 11 As originaly proposed, the script, SC:4~gfixed and “predetermined” does not abide by this c’tuuacterization, but the more recent ;vork conducted at the Yale 4.1. Project (Schank and Abelson 1!177a, B’$7+Yb) does. 35
63,.Sharon / Linguistic indicators
36
lines for what to observe, look for and check. Minsky’s characterization of’ the frame is representative of this line of thinking. A “‘Frame”, Mimky (1975) says, “‘is a data structure for representing a stereotyped situation, like being in a ca!.rtainkind of living room, or going to a child’s bdrthday party. Attached to each frame are several kinds of information. Some of the information is about how to use the frame. Some is about what one can expect to happen next. Some is (about what to do if these expectations are not confirmed”. Differently put,“A frame 1s a collection of questions to be asked about a hypothetical situation: it specifies issues to be raised and methods to be used in dealing with them”. In other words, ths: frame can be viewed as an organized matrbr of slots for &en states of affairs, assigned with specific terminal values on the basis of the particu?ar state of affairs&to which the frame is applied. However, claims l%nsky, “I cQqjecture that frames are never stored in long-term memory with unassigned terminal values. Instead, what really happens is that frames are stored with wea.kJy-bound default assignments at every terminal”. The concept of the frame has gained great popularity, but it has also raised much criticism. It has been noted that it is abstract, genera and non-committal (Drescher and Hornstein 1976; see also Winogr Id 1977). Indeed, it is not clear how frames can be upheld or refuted by observation and testing. In particular, no criteria have ever been given for deciding whether a given piece of information be exgllcitly specified in the frame - or, for that matter, in any other representation - or not. In the present note I try to point out a locus in which !;uch a criterion is, in fact, found. Specifically, I discuss two fa.milies of linguis?ic phcziomena: the definite article and negation. On the one hand, these phenomena seem to blf easily explicated within a framework taking into account semantic representaticjs;s !.ike the ones noted above; on the other hand, these linguistic phenomena might serve as independent indicators for deciding what to include in the representation. Given the great similarity between the different constru.:ts oroposed in the literature, md in l@ht of the great influence exercised by frames, will make aLl future reference to this last construct. The arguments made here, however,, are general and their relevance need not be confined to the Minskyan frame proper [2]. Let us, then, start with the defmite article. The environments in which the definite article is -usedmay be charar;ierized as follows: ) (a) The item introduced by the article is specific. (b) The item introduced by the article has already been mentioned in the conversation or it may be otherwise \?etermined by the context in qutl:stion.. [21 irs demonsrrative of this similarity, let me quote Charnlak’s (1977) defiI1itionof the frame - “A large body of information,expressedin a computer usableformalism&out a single topic where the facts are richly interconnected and which, while typically consulted as a whole consists of basic units (facts) which are ir~dividually used” - and. note that actu;:ll!ly it is a fair
characterizationof the script.
B. Shanon / Linguistic indicators
37
(c) If the item introduced by th_e zrtizle is unique, (b)Iis relaxed [3] . Basically, (*) states that the deGnite article rnaj be used only when determination of reference is possible. In other words, there should be a possibility for the establishment of a link between the item introduced by the def;Wte article and another item which serves as an anchor to it. Condition (a) specifies a prerequisite for this possibility, whereas condition (b) states that the link established may be either lin/@tic (a previous verbal instantiation) or a non-verbal, environmental one (e.g. ostension, in which the anchor is the very object to which one refers). Finally, condition (c) points out that when the -Aass denoted by the item introduced by the definite article is a singleton, no problem regarding LeterminAion cf reference obtains even when r:?oexplicit referential Sink is establis3ed. The conditions stated in (*> are demonstrated by the foilowing senl,ences: (1) Most people haven’t heard of the General Theory of Relativity. (2) The girl John dated is my neighbor’s friend. (3) Don’t touch the wire! In (1) the definite article is used with one item which is unique and well-defmcd. As a consequence, (c) applies, and the anchors specified in (b) are not required. In contrast, the two other sentences demonstrate that links to anchors are required wh.en the class is not a singleton. Sentence (2) exemplifies a linguistic I&-&:unless John dated only one girl the sentence cannot be well-defined when there is no prc rious mention. Sentence (3) illustrates a non-verbal link: the wire may not have been r,rentioned before the utterance at hand, :.U the use of the defmite article is appropriate . Our diszussiori will a‘ocuson several csses which seem to violate (*). As a first case consideir : (4) Pierre se lave les mains. This sentence has a coreferential reading 141. Its Engl 1 rendcdw, may be read either coreferentially or not:
W,
however,
(5) Pierre l&rashes: & hands.
[3] In nl’l’ering (IF) as a charucterization for the use of the definite ar?ls!e ! am Lcusing on types of environments which Go..--* the &finite article to ‘be used. Irrelevant to this discussion are some J,P the philosophical problems commonly associated with the definite arrlcle: the ontology of references, different modes of reading, generic usages and the like. [ 4 ] 1:us’ the terrn “coreferentiality” in a broad sense. Strictly speaking “hands” is not coreferential wi:lI “Pierre”, but the possessor of hands is. This use of term sho\*ld be clear from the context and CloYed not affect xhe reading.
B, Shanon / Linguistic indicators
38
The literal translation of (4), (61, is ungrammatical, a:nd th.at of (S), 1[7), is not coreferen tial : (6) * Pierre washes the ha&. (7) Pierre lave ses mains. The French examples are somewhat deficient in that they are confolrnded with the appearance of the reflexive pronouns se in the sentences with corefet*ential reading., and its absence in the sentences with noncoreferential one. This confounding, how.. ever, is iess significant than it may appear. The I-Iebrew translations of tire FrenchL sentences, for example, are free from it. In particular, in Hebrew one uses the identical verb in both coreferential and non-coreferential readirsgs, Thus, the Mebrew version of (4) Is (6), and that of (7) is (9). (8) Pierre rochetz et ha-yadayim. Pierre washes obj. the-hands. (9) Pierre rokhetz et yadav, Pierre washes obj. hands-his. For the sake of easier reference, the following discussion is based on the French examples. Sentence (4) is interesting because even though here are many hands (i.e. the item introtluced by the definite article is not specific:l, and dtispite the lack of previous mention or particular contextual identification, it is well-de!lned. In other words, even though (*) is not met, (4) is an appropriate sentence. lndeud, it poses no difficulty even in the artifical isolated context in which it appears irere. E~luitively, the interpretation of the sentence is based o:n the following rationale. Usually, people wash their own hands, hence “‘hands” in the given sentexlces is naturally associated with “Pierre’“, the washer. To put it in other words, mani~rw!atingobjects (and in particular, body parts) which beiong to oneself is the usual, unmarked case; as a consequence no explicit indication of possession is required. This rationale may be regarded as an instantiation of the Cricean maxim of quantity (CZce 1975). It is as if the specification of the possessive pronoun is considered by *r.helanguage as more “expensive”, than that of the definite article. Hence, in the unmarked case the article, and not the pronoun, is used. It is significant that the iraterpretation is based on pragmatic grounds, and not on purely semantic ones. i:ir other words, co-reference as such is not sufficient for the employment of the “cheaper” linguistic device. This is demonstrated by the fact that the use of the definite article in (10) does not imply that the book is John’s: (10) John re,ads the boo.k.
B. Shmon / Linguistic indicators
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A.3hinted above, the phenomenon noted here is not limited to body parts, but obtains whenever the particular referent is considered “most natural”, ;znd as such does not require furthe], specification even when no explicit anchor it; provided. Sentence (1 I) is an example of a use of the definite article with an unmarked referent other than a body part: (11) II est all6 a la maison. He went to. the house. He wl;nt home. A second case not covered by (*) is exemplified by (I 2) and (13): (12)1John cirne to Mary’s birthday, but forgot ‘.obring the present with him. (13) When l’om flew for the firs: time, he was \.ery eager to meet the stewardess. The sentl:nces differ from sentences (4) and (7) in that their analysis is not corlfind t;~ the reaIm of language proper (as exemplified by the Gricean maxims) but involves :he consideration of more g:neral cognitive structures. In par titular, the use of the definite article in these sentences is not tied to a particular semantic phenomenon such as the determinatitiir of possession relations, but bears on the speaker’s kncwledge of the world. Sentences (12) and (13) are not unmarked cases which correspond to more informative marked ones, yet, given the situation, the special identiry of both present and stewardess is clear. The present is the one John boug!rt for Mary, the stewardess is one attending Tom’s plane. There is nothing “usual” or “unmarked” about the!:e particular assignments, moreover they need not be unique (i.e. there could be mo:e than one stewardess on the plane). Yet, these cases pose no problems of interp:etatior,. When one goes to a birthday party one btigs a present. Hence the present is the one one bought and is supposed to bring, A similar argument holds for the stewardess and the plane. These ideas bring us back to Minsky’s Frames ecifidy, if the item introduced by the definite article appears as a terminal v in the relevant frame, and if its default value is implied, no explicit specificati an IanchDr is needed Thus, Charniak (1972) we note that the birthday frame includes, among other things, PRESENT as a terminal value. Givl:n. that this item is actu&/ specified in the frame, sentence (12) is fully understood even when uttered in isolation. The definite article is used even though herVe are many presents in the world, and no previous mentioning was noted. Sentence (13) is accounted for in a similar fashion. The case exemplified by (4) r-nay be analyzed on similar lines as well: “one’s own” is lhe default value for possession relations. This assignment, however, unlike that noted in (12) and (13), is very general, and imphes no particular Frame The t\vo cases introduced here as violations of (*) may, indeed, be viewed not as counter-examples to this characterization, but rather as ones that extend it. They demonst;.ate that in addition to verbal and contextual anchors there are also prag
Rather than linking the item introduced by the definite article to another verbal description or an actual referent, the speaker may link it ‘to a conceptual representation a.ssumed to be shared by the members of the given com-
maticcognitive
ones.
munity .
Following are PJrther usages of the defmite article which are not covered by (*) but which may be explicated in the manner just suggested. Question (14) and the answer to it (15) were collected in an, empirical survey in which pnswers to questions were investigated; the conversation actually took place in a restaurant setting
. Fl .
(14) Why did you read the menu? (15) I read the menu because the waiter gave me one. The exchange is interesting because (15) may be appropriate even when more than one waiter is present in the restaurant in question. Specifically, it offers a case where the very first prerequisite of (*) is violated: the item introduced by the defiiite article is not specific yet determination of reference poI;es no probiem. That this is, indeed, the case is further demonstrateId by the fact that (16) is not an appropriate reaction to (15). (16) Which (with rising intonation) waiter? This is unlike (18), which would have been an appropriate reactiorl to (17), ha.d it, (17), been given as an answer to the original question (14): (17) Because the pilot gavs me one. (18) Which (with rising imonation) pilot? The foregoing examples suggest tha: +Lhecognitive link may nut be subject to condition (a) of (*). The Frame offers an anch.or (in our case, WAITER) which is weh-defmed even though the object in the real world which corresponds to it is not a single, specific one. The phenomenon just considered is particularly noted when function rather than specific reference is of interest. Thus, consider sentence (19) when uttered at a dinner table on which there are two salt-shakers: (19) Would you pass the salt-shaker please? The use of the defmi?e article is perfectly appropriate even t ough ithe item it intro15 1 Restaurants - amongst other settings - were chosen in obtious reference to Schank’s work. The analysis of the entue corpus of answers is tht: focus of research which is now in progress.
B. Shanon / Linguisd?c indicators
41
duces is not unique, no previous mention need have been made to it, and the speaker need not accompany his request with a gesture. None of tie conditions of (*) is observed, yet the responder will have no difficulty in handing over one of the salt-shakers. (19) is appropriate because what is at stake is the est rblishment of a link t,o the “salt” as presented in the relevant frame; the choice of 1:particular saltshaker as its value, however, is immaterial. A similar use is found in corn non functional expressions: (20) (21) (22) (23)I
He went to the post office. She went to the grocery store. They went to the laundry. Yesterday, I went to the delltist.
Note that in these sentences tht action denoted by the verb is not taken literally, but rather as a place holder for a routine deduced from the meaning of the object that follows. Going to the grocery store, for example, is not equivalent to walking or driving from one’s home to thi: grocery store. So far I have referred to the notion of the Frame in order to explicate various seemingly deviant usages of the definite article. The opposite course, however, is possible as well. In other words, the usages in question may be !aken as indicators marking the identity rjlt the values spec:Xied in the Frame. Specifically, if an item is intro&iced by the definite article in a way which violates (*), one can conclude that item is specifically stored in the cognitive Frame [6]. While the main topic of the present paper is the definite article, I would still like to make some additional comments regarding another linguistic construct, negation. The comments made regarding negation are not as developed as the ones having to do witit the defmite article, but they lead to identical conclusions with respect to the relationship between language and conceptual representation. Thus, consider another verbal exchange collected in the survey mentioned above. The exchange took phce in a university cafeteria: (24) Why did you pick the food by yourself? (25) Because I saw that there was no waiter. Sentencs (24) is rather curi:Dus: one sees that things are, but how can one see that =-jple By wiay of analyzing this e,., _.__ let me make a short digression. Even though affirmative and negative sentences are completely symmetric from a logical point of view, pragmatically they are very different. People describe the world as it is, rather
[6] For further discussions of the definite article in the artificial intelligence ‘kiterhture,set Schanlc and Abelson (1977a).
42
B. Shanon / Lirtguistic indicators
than according to what it is not. Thus, even though both refer to an identical state of affairs in the re&!world, pragmatically (26) and (27) are different: it is natural to use (26), but not (27): (26) H is in the room, (27) A, a.., G, I, .. . Z are not in the room. Evidently, one may, and one does, employ negation. However, the “pragmatic value” of affirmative and negative sentences is not the same. In uttering an affirmative sentence a speaker commits himself only to the truth of the statement he makes. In contrast, in utt&ng a negative statement a speaker not only states that a certain state of affairs does not hold but that l!l\ere is something special about the fact that it doesn’t. The higher value is :jssociaied with a higher price: a speaker would not utter a negative statement unless he has sp+:ci,llreason to do so. In our case, (27) cannot be uttered unless A, .... G, I, ... Z have disappeared, are expected, or are supposed to be present; no similar assumptions ne2d to be made in conjunctinn CIV.. with ..*.a. (361 \W’,.
Returning to (24)---(X) we conclude that answer (25) could not have been given unless the presence of ‘“waiter” was assumed somewhere. This alleged place, however, is not provided in the context nor does it seem to be particular to the speaker’s experience, 3s would have been the case with (26). Rather, the normalcy c--f(25) may be attributftd to the presence of the negated object in a mental frame, a Minskyan Frame, which is relatively independent of the r:xperiences of the p:rrticular speaker and is sh;ired by the members of the cognitive community. The Restaurant frame, as we noted, contains WAITE:Ras one o i its values. The fact that (28) is not a normal answer to (24) indicates that PLANE iz not in that frame: (28j Because I saw that there was no airplane th:re. It should be emphasized that the reason expressed by (28) might have indeed been the one underlying the speaker’s behavior. Yet it would ncbt have been appropriate for him to give it as a justification without an additional ‘“story’“.The waiving of this requirement, we would say, is indicative of the nega:.ed entity “being in the Frame”. Other special usages of negation were found in an empirical survey of how people describe rooms. As expected, practically all the sentences in t:re descriptions were affirmative. In a corpus of more than 20@sentences, however, two cases were encountered in which the negative mode was en ployed: (29) We don’t have any furniture. (30) The ceiling is without a lamp. Neither “furniture” nor “‘lamp” were mentioned earlier in the description. Just in
B. Shanon / Linguistic kdicators
43
order to emphasize the special status of (29) and (30) note the great peculiarity of Etatements such as (3 1) or (32): (3 1) We don’t have any diamonds in the room. (32) The ceiling is without carpeting. The explication of these facts should, by now, be obvious. “Furniture” is specified in the Room Frame, but “diamonds” is not. Similarly, “lamp” is specified in the ceiling sub-Frame, but “carpeting” is not. To conclude, the construcions discussed here may be considered from a common perspective. These conslructions require an antecedent reference point. In ordinary phrases this point is established either explicitly in the linguistic structure itself or implicitly on pragmatic grounds, including non-verbal communication, assumed shared knowledge of’ the speaker-hearer and common expectations. The examples noted here did not belong to either of the two type*. It was suggested that they constitute examples of a third type in which reference is made to cognitivV1* litp Mirr~t~l’n C*r~nid~l :,-C-m-,- -_a =*:-.-.-.Jr--&a.‘#ctnlf)llr~f “L*U”C”a”” llzI”*.Ulr*RJ 3& lQdlIG3. 1Cm~r+har UIUIGI,*XPLA~ WlICll+Ir~-n LiIC3C IIIJltlllc;CJ a1c vlc"wcu llUlll another perspective, they may be taken as indicators to “What is in the Frame”.
eferences Bobrow, D.G. and D.A. Norman. 1975. ‘Some principles oi memory schemata’. In: D.G. Bobrow and A. Collins, eds., Representation and understan iing. New York: Academic Press. pp. 131-150. Bobrow, D.G. and T. Winograd. 1977. An overview of KRL, a knowledge representation language. Cognitive Science 1: l-46. Charniak, E. 1972. Toward a model of childrefl’s story comprehension. M.I.T. Artificial Intelligence Laboratory. Charniak, E. 1977. A framed painting: the representation of ;t conlmon ti,-nse knowbdge payment. Cognitive Science 1: 355-394. Dresher, E. and N. IIornstein. i976. On some supposed contrihlr p~on9of artificial intell’igence to the scientific study of language. Cognition 4: 321-398. Crice, H.P. 1975. ‘Logic and conversation’. In: P. Cole and J.L. Morgan, eds., Syntax and semantics, 3. New YorT.: Academic Press. pp. 4 l-58. Iv’inqky, M. 1975. ‘A frac .ework for relzresenting knowledge’. In: P.H Winston, ed., l%e psychology of computer vision. New York: McGraw-Hill. pp. 2 1 l- 27 ;’( Sc,jank, R.C. and R. Abelson. 1977a. Scripts, plans, goals and understanding. New York: Halsted. Schank, R.C. and R. Abelson. 1977b ‘Scripts, plans and knowledge’. ln: P.N. Johnson-Laird and P.C. Watson, eds., Thinking: readings in cognitive science. Cambridge: Cambriage University Press. pp. 42 l-432. Schank, R.C. and the Yale Artificial Intelligence Project. 975. SAM - a story understander. Yale University computer science research report 43. Winograd, T. 19’75. ‘Frame representation and t’he declarative-procedural controversy’.In: D.G. Bob:ow and A. Collins, eds., Representation and understanding. New York: Academic Press. pp. 185-210.
Winograd, ‘T’.1977. On some cantested suppositions study of language. Cognition 5: 15 I- 1.79. Benny Sh.anon,
ofgenerative linguistics about the scientific
born 19 8, studied philosophy and linguistics as an undergraduate at Tel Aviv University and obtained an M.A. in linguistics ainda Ph.D. in psychology at Stanford. Taught at M.I.T. Ynd is presently at the Department of Psychology of the Hebrew University. interested in the indastigation of semantic prablems from several different perspectives: the cognitive experimel;tal, the theoretical linguistic, the neuropsycholegical and that of cognitive science and artit’tcialintelligence.