Semantic pliancy through input and settlement in dialog (Which means through Miscommunication) - PowerPoint PPT Presentation

semantic plasticity through feedback and accommodation in dialogue meaning through miscommunication l.
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Semantic pliancy through input and settlement in dialog (Which means through Miscommunication)

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  1. Semantic plasticity through feedback and accommodation in dialogue(Meaning through Miscommunication) Miscommunication Workshop QMUL, London, January 26, 2006 Staffan Larsson Göteborg University

  2. Overview • Introduction • Negotiation, feedback, accommodation • Semantic plasticity • Meaning accommodation • Conclusions

  3. Introduction

  4. Questions • What goes on in dialogue? • Information exchange, but also: • Explicit and implicit negotiation of meaning (and other aspects of language) • Which mechanisms govern these processes? • How are these processes related? • What is meaning? • Is meaning private or social? In what sense? • How is meaning and use of language related? • What is the role of formal representations in a theory of meaning? • What is the role of subsymbolic cognition in a theory of meaning?

  5. Two kinds of coordination in dialogue • Information sharing • Sharing of symbolically / linguistically represented information • Grounding (updating common ground) • Coordination of linguistic resources (language system) • Semantic change and adaptation (& linguistic change in general) • Adaptation of linguistic resources to activity or situation • Adaptation of linguistic resources to specific partner • Ad-hoc adaptation to a specific conversation • Long-term changes in language over time • Linguistic coordination is necessary for information sharing • Establishes shared meaning of linguistic constructs used to share information

  6. Work on dynamics of information sharing • Starting point: language games (Wittgenstein 1953) • Formal descriptions of language games • Dialogue grammars (Sinclair & Coulthard) • Dialogue games as finite state automata (Lewin et al) • Game-theoretical accounts • Carlson 1983 • Jaeger et al (recent) • … and lots more… • Research on formal and computational accounts of dialogue games (SemDial workshop series 1997-); TRINDI and later projects • Dialogue games as Information State Updates • In terms of sequences of dialogue moves • Moves trigger updates to a Dialogue Gameboard (which is part of a more inclusive Information State) • Example: Issue-Based Dialogue Management (Larsson, Ginzburg)

  7. Work on dynamics of language system • Halliday • Meaning potentials, adapting linguistic resources to specific activities • Clark • Creative language use: creating verbs from nouns • Brennan • Conceptual pacts, lexical entrainment • Healey • Emergence of shared vocabularies in groups vs. across groups • Cutler et al • Phonetic plasticity • Pickering & Garrod • Alignment of multiple levels in dialogue • Steels et al • Emergence of shared categories through social and embodied linguistic learning in robots

  8. Common theme in work on dynamics of language • How new vocabulary emerges • How words acquire or change meaning through social linguistic interaction • Additional themes • Language is activity-specific (dialogue games) • Language and embodiment

  9. Symbolic and nonsynbolic/subsymbolic • According to Dreyfus, Brooks and others, cognition is not based on symbolic representations • Dreyfus claims that human language understanding relies on a background which cannot be represented as a set of facts • Still, human language is the prototypical symbol system so linguistic cognition must involve symbolic representations • How does symbolic and nonsymbolic cognition interact in language understanding and dialogue in general?

  10. Some theoretical issues • Give accounts and models of • Individual usage dispositions and how they are updated • How social meaning is related to usage dispositions • How meaning is negotiated, tacitly and explicitly, and how this relates to updates of usage dispositions • Dialogue games for meaning negotiation • Tacit negotiation through feedback and accommodation • Integrate account of semantic dynamics with existing accounts of dynamics of symbolic (linguistic) information updates, into a general account of alignment/coordination in dialogue

  11. Negotiation, feedback, accommodation

  12. Three important processes of coordination in dialogue • Explicit negotiation • “Negotiation” used here in weak sense of “reaching a joint decision” (may be antagonistic or cooperative) • E.g. ostensive language games (Steels & Belpaeme 2005: “the guessing game”), explicit verbal definitions • Feedback • Signalling perception, understanding, acceptance • Signalling failure to perceive or understand; clarification; rejection • Guides coordination of DGB (Grounding) • >Also: guides coordination of language use • Accommodation: Adapting to the behaviour of other DPs • Adapting to presuppositions (adapting the DGB) • >Also: adapting to language use (adapting linguistic resources)

  13. Accommodation • Conversational scoreboard • Dialogue gameboard (DGB) • (Part of) Common Ground (CG) • (Shared part of) Information State (IS) • Lewis (1979): • Dialogue tends to evolve in a way that makes any move count as correct play • “If someone says something at t which requires X to be in the conversational scoreboard, and X is not in the scoreboard at t, then (under certain conditions) X will become part of the scoreboard at t” • Has been applied to referents and propositions, as parts of the conversational scoreboard • E.g. “Bo snores” or “My cat is hungry” presupposes referent in DGB • If no matching referent in DGB, hearer may ask clarification question • but only after failure to accommodate

  14. Issue-based Dialogue Management • (Larsson, Ginzburg) • DGB includes a stack of Questions Under Discussion (QUD) • Answers require a matching question before they can be accepted and integrated RULE:integrateAnswer PRE: in( $/SHARED/LU/MOVES, answer(A) ) fst( $/SHARED/QUD, Q ) $DOMAIN :: relevant( A, Q ) EFF: ! $DOMAIN: combine( Q, A, P ) add( /SHARED/COM, P )

  15. Typical human-human dialogue S(alesman), C(ustomer) S: hi C: flight to paris S: when do you want to travel? C: april, as cheap as possible

  16. Typical human-human dialogue S(alesman), C(ustomer) S: hi C: flight to paris S: when do you want to travel? C: april, as cheap as possible How do you want to travel? Where do you want to travel? What price range?

  17. Question accommodation • If questions are part of the DGB, they too can be accommodated • If the latest move was an answer, and there is an matching question which is relevant in the activity at hand, then • put that question on QUD

  18. Coordination and accommodation • “... someone says something at t which requires X to be in the conversational scoreboard, and X is not in the scoreboard at t...” • This may indicate a case of lack of coordination • but may also be used as a strategy for conveying implicit information (Grice) • In any case, accommodation can be used to adjust to some presupposition of what is shared

  19. Feedback in dialogue • Feedback: signals for achieving coordination (alignment, grounding) on several levels of action (Allwood, Clark) • Contact / attention: +/- • Perception: +/- • Understanding: +/-/? • Reaction: accepting and rejecting utterances • The hearer can react to whole utterances or sentences, or to some part of an utterance • A word, a phrase, a grammatical construct, or in general any linguistic construct • Example: Clarification Requests (Ginzburg)

  20. Grounding • ”To ground a thing … is to establish it as part of common ground well enough for current purposes.” (Clark) • Common Ground includes • general facts about the world (commonsense knowledge) • More specific facts about the world (e.g. facts about history) • facts about words (dog can mean ”canine animal”) • and more • Henceforth, we will use grounding in a more limited sense • The process of adding information to the ”Dialogue Gameboard” (DGB) or Conversational Scoreboard

  21. Semantic plasticity

  22. Structuralism • The sign relation, i.e. the connection between words (linguistic form) and concepts is arbitrary • The way that linguistic material is divided into words is arbitrary • The way that the world is divided into concepts is arbitrary • Focus on study of language as a structure (langue); the concrete use of language (parole) assumed too unruly for scientific study

  23. Poststructuralism • Langue is continuously being affected by parole • Words change their meanings over time as a result of language use • If or concepts determine how we understand the world... • Concrete language use changes our understanding of the world • Communication is not (just) transmission of information • Science studies, Critical Discourse Analysis & related disciplines study how people fight over the use of certain words; “man”, “gender”, “gene”, “terrorism”, …

  24. Phonetic plasticity • Cutler, McQueen, Norris (2005) • ACL paper • Experiment: • Ambiguous phoneme /?/ between /f/ and /s/ • Group A hears words where /?/ replaces /f/, e.g. ”carafe” • Group B hears words where /?/ replaces /s/

  25. Result • For group A, the /f/ category became more inclusive (tested by phoneme categorisation) • For group B, the /s/ category became more inclusive • Exposure to /?/ in non-word context had no effect • Effect generalised to new words, and thus facilitates word recognition

  26. Semantic plasticity • As with phonemes, semantic categories can (presumably) gradually expand, contract, and shift

  27. Kinds of semantic plasticity • Semantic systems exist on several levels • National • Regional • Domain, activity, language game • Personal (idiosyncratic) • Particular interactions (dialogues) • Semantic system can be adapted • Example: “the one with the handle going across”: map “handle” to certain shape on card (Brennan) • to a new activity or domain • to a certain individual (who has an idiosyncractic way of using some concept) • to a certain interaction (ad-hoc) • Associated issue: • When & to what extent does “idiosyncratic” usage of some word in a single dialogue affect its meaning in general? • Plasticity vs. elasticity • Indeed, are there “meanings in general” which are adapted to specific activities or are meanings just borrowed from other (equally specific) activities?

  28. Sketch of a formal general account of semantic plasticity • Meaning emerges from a multitude of interactions where the DPs of a linguistic community shape each other’s usage dispositions • A language-user A observes some linguistic construct c being used in a set of situations Sc (situational collocation for c) • A generalises over Sc; this generalisation we call the usage disposition [c] • The way [c] is updated after a use depends on the feedback given by other DPs • A: “Alignment is automatic” • B; “Uhuh” / “I agree” / “Automatic?” / “No way!” / “Eh?” / ... • [“automatic”] may get updated for A or B or both

  29. Usage dispositions • Instead of modelling semantic plasticity directly, we will model usage dispositions • Private (“in the head”), but socially conditioned • Do not completely determine usage, but affects it • Dispositions are affected by feedback • The usage-dispositions of the members of a linguistic community must be sufficiently similar to allow for coordinated behaviour • The model will allow for creative language use • The following is an abstract “skeleton” account that can be filled out in may different ways

  30. Situational collocation • Abstractly, each individual A can be associated with a situational collocation ScA • Contains the situations in which A has observed c to be used (including uses by A) • ScA = { s | c was observed by A to be used in situation s } • We won’t say more about what a situation is here; can be fliled out in various ways to include e.g. • Linguistic context • Referential context • “Connotational” aspects

  31. Successful and unsuccessful uses • Consider a situation where c is used in s, and c is addressed to B. • B can understand c or fail to do so • Provided B understands (or thinks he understands), B can choose to accept or reject c • In the following, we will (for the most part) restrict feedback to • acceptance (and understanding) • negative understanding (and no acceptance) • positive understanding, rejection • Successful use: understood and accepted • Unsuccessful use: not understood, or rejected

  32. Usage dispositions: more • Presumably, an individual A somehow generalises over situational collocations • (Alternatively, remember completely all situations where each constructs was used) • We refer to this generalisation as A's usage disposition for c • An agent A’s usage disposition for c, written as [c]A, is a function of the situational collocation for c • [c]A = fdisp-A(ScA) • Related points: • This function may capture any aspects of the situation that are relevant to language use; physical, biological, psychological, sociological, linguistic • To handle ambiguity, this function should allow for differentiated generalisations over subsets of ScA • Does the generalisation function differ • Between speakers? • Between linguistic categories (nouns, verbs, grammar rules, …)?

  33. Judging appropriateness • We assume that something like “estimated degree of appropriateness” or “consistency with previous uses” plays a role in language use • Appropriateness of using c in s is a function of the usage disposition for c, and s • appr(c, s)A = fappr([c]A,s) = fappr(fdisp(ScA), s) • In a simple case, we can model fappr with a boolean function (either appropriate or non-appropriate) • Or it could be a numerical value, e.g. between 0 and 1 • Related points • This is not meant to imply a conscious judgement… • … nor that it is relevant or even possible to say whether the estimation of appropriateness is “correct” • May be used to model some notion of “linguistic intuition” governing own language use including how one gives feedback

  34. Indeterminacy • Upon hearing c in new situation s, A’sreaction (the kind of feedback A gives) partly depends on [c] • But A’s behaviour is not determined by [c], or even Appr(s,c) • This means that A can understand and accept uses of c that deviate from [c] • A’s own future uses of c are partly determined by [c] • Again, A’s own use of c is not determined by [c], or even Appr(s,c) • A can use c in ways that deviate from [c]

  35. Disposition updates • If follows from the definition of dispositions that whenever a construct c is used, Sc will be extended, and so the usage-disposition [c] may change • This is a disposition update • Disposition reinforcement • This use of c is consistent with usage disposition, i.e., c is appropriate in s • No drastic change; previous disposition is reinforced • Disposition revision • This use of c is non consistent with usage disposition • More or less drastic change of meaning; previous meaning is revised • Related points • Arguably, all language uses are creative since all situations are different • But intuitively, some uses are more creative than others • To what extent can we distinguish revision from reinforcement? • Are updates continuous or discrete • Depends on the kind of linguistic construct? • Scalar terms, e.g. colour terms appear to be continuous

  36. The usage equation • use(c, s)A = fuse( fappr(fdisp(ScA), s), X ) • What does this mean? • Whether A uses c in s depends on • s: The current situation • ScA: Situational collocation for c - previous situations where c has been used, in A’s experience • fdisp: The way A generalises over these • fappr: The way A uses this generalisation do determine the appropriateness of c in s • Any additional factors X • the ways in which these, in conjunction with the appropriateness judgement, affect whether c is actually used (fuse)

  37. Possible outcomes of using c in s

  38. From usage dispositions to meaning • The meaning of a construct c in a linguistic community L emerges from the coordinated use of c by the members of L • Meaning is inherently social, and arises out of coordinated behaviour in a linguistic community • In interaction, members of a community “mould” each others’ usage dispositions by giving feedback and accommodating usage • This keeps language use sufficiently coordinated for meaning to arise • By modelling plasticity of usage dispositions, we indirectly model semantic plasticity

  39. Meaning accommodation

  40. Possible outcomes of using c in s

  41. Meaning accommodation • For each construct used in an U, the addressee in a dialogue is (usually) expected to react if he thinks a construct in U was incomprehensible or inappropriately used • If a breakdown occurs during interpretation of U by B, it may be due to a mismatch between the situation in which c was being used by A, and B’s usage disposition for c • The addressee B may now • reject this use of c explicitly: negative feedback on understanding or acceptance level • or quietly alter B’s usage disposition for c so that c can be counted as appropriate after all. • The latter process we may call usage accommodation, or meaningaccommodation • This extends the notion of accommodation beyond the DGB, to include the language system

  42. Two variants of meaning accommodation • Accommodated creative use • Speaker non-appropriate, Hearer non-appropriate, successful • New use not “appropriate” according to speaker but speaker tries it anyway • revise [c]A and [c]B • Accommodated conservative use • Speaker appropriate, Hearer non-appropriate, successful • Not really creative since the speaker followed her appropriateness judgement, but hearer had not heard that use before • reinforce [c]A, revise [c]B • Example (of either of the above) • (in 1991 or so) • A: What are you doing? • B: I’m surfing the web • A: ... Ah, OK.

  43. Latent subgames and “gears” in dialogue • Cohen (1978), Severinsson-Eklundh (1983) • Dialogue involves “latent subgames” or “tacit moves” that can become explicit if necessary • Example: referent identification subgame, perception subgame • A: Pick up the red one • B: (hears “pick up the red one”) • B: (identifies red object; there are two but only one has been discussed previously) • B: (picks up red object) • A: Pick up the red one • B: (hears “pick up the red one”) • B: Do you mean this one? (points to x) • A: No, this one (points to y) • B: (picks up red object) • A: Pick up the red one • B: Pardon? • A: Pick up the red one • B: …

  44. Accommodation as tacit negotiation • Meaning accommmodation can be seen as tacit negotiation of meaning • When dialogue proceeds smoothly, speakers shift to high gear and assume that latent subgames will succeed • Optimistic strategy • Tacit moves / games • When problems (breakdowns) occur, participants shift into low gear and give explicit feedback, request confirmation, etc. • Cautious strategy • Latent subgames are played out explicitly • Explicit negotiation can often be regarded as occurring in “low gear” • Accommodation can be seen as a tacit dialogue move(or game), which replaces an explicit subgame of negotiation

  45. Explicit negotiation vs. accommodation • Meaning can change as a result of explicit negotiation or accommodation • Explicit negotiation • Hearer detects problem and initiates negotiation subgame to resolve it • Accommodation • Hearer detects has problem understanding or finds utterance otherwise inappropriate or problematic, but nevertheless is able to adapt to the situation and proceed with the interaction • Commonsense background and general redundancy in linguistic interaction enables efficient tacit negotiation through accommodation

  46. Conclusions

  47. Coordination of meaning through miscommunication • “Perfect communication” • Perception, understanding and agreement are unproblematic • No negotiation, feedback or accommodation is needed • “Miscommunication” • Perception, understanding and agreement are fallible • Feedback is needed to monitor success • Accommodation is needed for efficiently adapting to differences in DGB and language system • These mechanisms enable coordination of meaning through the interactive adaptation of usage dispositions • Miscommunication is thus the very basis for linguistic plasticity and adaptation • If there was no miscommunication, language would be static and unadaptable • Unless changes where instantaneous and universal, which does not seem very plausible

  48. Summary • Three types of mechanisms for dealing with miscommunication • Explicit negotiation • Feedback • Accommodation • … enable coordination of... • Dialogue Gameboard updates • Dynamics of semantic system (semantic plasticity) • Coordination of DGB presupposes a sufficiently coordinated language system • In “low gear”, explicit negotiation of usage / meaning is played out explicitly • In dialogue in “high gear”, accommodation enables adaptation of usage dispositions (and thus coordination of usage) • Meaning emerges and changes not only as a result of explicit negotiation, but also as a “side-effect” of tacitly resolving problems in information sharing

  49. Additional material

  50. future work