On the reality of common ground

On the reality of common ground Matthew Harvey AMPRA 2014

2 www.newyorker.com

Three explanatory strategies

1.  The strong view: mutual knowledge

2.  The weak view: motivated or justified shared belief

3.  The radical view: shared circumstances

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The strong view: Mutual knowledge ¡ A code model of pragmatics

¡ Common ground is the set of propositions which: 1.  Are privately known by all interlocutors

2.  Are explicitly recognized as (1) by all interlocutors

3.  Constitute the context or conversational setting – they are available as premises for reasoning about intended meanings

¡  E.g., Grice 1957, Strawson 1964; Schiffer 1972.

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Motivating assumptions 1.  Methodological individualism

2.  The code view of language

The idea of mutual knowledge bridges the epistemic gap that these assumptions create between interlocutors.

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Common ground as mutual knowledge

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Utterance

Speaker Hearer

Speaker’s meaning

Semantic representation

Morphosyntactic rep.

Phonological representation

Phonetic representation

[Pragmatic rules/maxims] [Background knowledge]

[Situational knowledge]

[Lexical knowledge]

[Grammatical knowledge]

[Phonological knowledge]

[Articulatory expertise]

Hearer’s meaning

Semantic representation

Morphosyntactic rep.

Phonological representation

Phonetic representation

[Lexical knowledge]

[Grammatical knowledge]

[Phonological knowledge]

[Auditory expertise]

[Pragmatic rules/maxims] [Background knowledge] [Situational knowledge]

[Sensorimotor environment] [Impending events] [Previous events]

Implicatures

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Utterance

Speaker Hearer

Warn: [A] will make me late

[First talk of the morning]

[Speaker gets in taxi] Brentwood

UCLA

Event A: taxi takes a wrong turn

Implicatures

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Utterance

Speaker Hearer

Warn: [A] will make me late [Be perspicuous, informative] [Locations Brentwood, UCLA] [In taxi, time until first talk]



UCLA

[Be perspicuous, informative] [Locations Brentwood, UCLA]

[In taxi, time until first talk]


Implicatures

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Utterance

Speaker Hearer


I’m going the wrong way.

[Be perspicuous, informative] [Locations Brentwood, UCLA] [In taxi, time until first talk]



UCLA




“Ah, we seem to be taking the route that goes through Brentwood”

Implicatures

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Utterance

Speaker Hearer



“Ah, we seem to be….”

/ɑ wi sim tu bi tekɪŋ ðə…./

[ɑ wi sim tu bi tekɪŋ ðə….]

[“to take”, “route”, “go” etc.]

[present tense, 1SG, PP, etc.]

/ɑ/, /w/, /i/, /s/, /m/, etc.

[interdental frication, etc.]





/ɑ/, /w/, /i/, /s/, /m/, etc.

[Prosodic contours, etc.]




UCLA





Implicatures

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Utterance

Speaker Hearer








/ɑ/, /w/, /i/, /s/, /m/, etc.


S. is going the wrong way




[“to take”, “route”, “go”, etc.]


/ɑ/, /w/, /i/, /s/, /m/, etc.





UCLA





Implicatures

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Utterance

Speaker Hearer








/ɑ/, /w/, /i/, /s/, /m/, etc.


[A] Will make the speaker late

S. is going the wrong way




[“to take”, “route”, “go”, etc.]


/ɑ/, /w/, /i/, /s/, /m/, etc.





UCLA




Private and common knowledge ¡ Mutual knowledge cannot be accounted for by

a methodologically individualistic theory.

¡ Mutuality is the truth of four propositions: 1.  A knows that p

2.  B knows that p

3.  A knows that (2)

4.  B knows that (1)

¡ Any person can only be completely certain of one of those four propositions.

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Infinite regress “The Mutual Knowledge Paradox is a philosophical puzzle arising from the need to postulate an infinite series of statements of the kind I know that x because I know that you know that I know that you know that I know … and so on … that x.” (Lee 2001, p. 26)

“As with other phenomena in linguistics in which a person is said to “know” an infinite number of things, the knowledge is not enumerated as an infinite list, of course, but is implicit in a finite recursive formula. In this case, it could be the formula y: Everyone knows x, and everyone knows y.” (Pinker, Nowak, & Lee 2008, p. 837)

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Theory and reality 1.  Real conversations only ever involve finite

chains of reasoning (of course) 1.  (And we usually don’t think through any iterations of

that formula at all)

2.  Mutual knowledge tells us what it looks like for knowledge to be mutual, rather than explaining how knowledge comes to be mutual in the first place

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The weak view: Justified shared belief ¡ Non-certainty about sharedness

¡ Non-certainty about truth

¡ We always have a reason for taking some proposition to be common ground

¡  E.g., Barr & Keysar 2005; Clark 1996; Lee 2001; Lewis 1969; Pickering & Garrod 2004; (maybe) Stalnaker 1999, 2002

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Presupposition ¡  Pragmatic presupposition: “Sorry I’m late, I had to

drop off my sister.”

¡  Speaker presupposition

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Implicit common ground ¡  Interactive linguistic alignment ¡  Lexical choice

¡  Syntactic construtions

¡  Clarity of articulation

¡  Speech rate

¡  Shared experience leads to convergence in expectation and anticipation, which produces the effect of common ground without being conscious, verbal, or even necessarily cognitive.

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Perceptual common ground

¡  “Perceptual co-presence” as justification for shared belief

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http://www.thefarside.com/

[Authority → directness] [Obligations prompt action]

[[A] is shared visual focus]

Referential objects

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Utterance

Parent Child

Direct child: put [A] in [B]

Child must place A into B

“Throw that out”

/θro ðæt awt/

[θro ðæt awt]

[“to throw”, “that”, “out”]

[d. objects, null subjects, etc.]

/θ/, /ð/, /r/, etc.

[glottal stops, voicing, etc.]

Pick up [A], put in [B]

I must place A into B


/θro ðæt awt/

[θro ðæt awt]

[“to throw”, “that”, “out”]

[d. objects, null subjects, etc.]

/θ/, /ð/, /r/, etc.

[word boundaries, etc.]

[Authority → directness] [Obligations prompt action] [[A] is shared visual focus]

[Child leaves] [Child drops candy bar wrapper]


Object A Object B

Perceptual common ground

¡  “Perceptual co-presence” as justification for shared belief

¡  Problem 1: we’re not very good at this

¡  Problem 2: we tend to rely on salience rather than accessibility to others

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http://www.thefarside.com/

The radical view: Shared circumstances ¡  State of affairs in conversational contexts are not

reasons for accepting a proposition as common ground; they are the common ground

¡  It’s shared circumstances themselves, rather than our knowledge about them, that guides our understanding

¡ On this view, common ground is both real and concrete, but it is not uniquely linguistic, it is not an individual capacity, it is not logical or computational, and it is not strictly cognitive.

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Conclusions

1.  Common ground is not real 1.  The strong and weak views have no clear

connection to what happens in actual conversations;

2.  The radical view has no unique connection to language

2.  We may need to re-think our commitment to methodological individualism

3.  There is tremendous potential for the development of a radical, non-code-view pragmatics

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References

•  Barr, D. J., & Keysar, B. (2006). Perspective taking and the coordination of meaning in language use. In M. Traxler & M. Gernsbacher (Eds.), Handbook of Psycholinguistics 2nd Ed. (pp. 901–938). Amsterdam, Netherlands: Elsevier.

•  Brennan, S., & Hanna, J. (2009). Partner-specific adaptation in dialogue. Topics in Cognitive Science, 1, 274-291Clark 1996

•  Duran, N., Dale, R., & Kreuz, R. (2011). Listeners invest in an assumed other’s perspective despite cognitive cost. Cognition, 121, 22–40.

•  Grice, H. (1957). Meaning. The Philosophical Review, 66(3), 377-388. •  Kecskes, I., & Zhang, F. (2010). Activating, seeking, and creating common ground: A

sociocognitive approach. Pragmatics & Cognition, 17(2), 331-355. •  Lee, B. (2001). Mutual knowledge, background knowledge and shared beliefs: Their roles in

establishing common ground. Journal of Pragmatics, 33, 21– 44. •  Lewis, D. (1969). Convention: A philosophical study. Cambridge, MA: Harvard University

Press. •  Pinker, S., Nowak, M. A., & Lee, J. J. (2008). The logic of indirect speech. Proceedings of the

National Academy of Sciences, 105(3), 833-838. •  Schiffer, S., (1972). Meaning. Oxford: Oxford University Press. •  Shockley, K., Richardson, D., and Dale, R. (2009). Conversation and coordinative structures.

Topics in Cognitive Science, 1, 305–319. •  Stalnaker, R. (1999). Context and Content: Essays on Intentionality in Speech and Thought.

New York: Oxford University Press. •  Stalnaker, R. (2002). Common ground. Linguistics and Philosophy, 25(5-6): 701–721. •  Strawson, P. (1964). Intention and convention in speech acts. The Philosophical Review,

73(4), 439-460. 24

On the reality of common ground

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