CAS LX 502

6b. Context and inference7.4-

Context and meaning

• Nearly everything one reads or hears requires knowledge of context to interpret.

• This can include:• Physical context

• I don’t know why they did it.

• Prior conversation• And then he just up and left.• Me too.

• Background/common knowledge• The President has resumed eating pretzels.

Background knowledge

• Generally assumed real-word/cultural knowledge, common ground, presuppositions of discourse.

• Probably not actually mutual knowledge (that is, propositions that are both known to the interlocutors and known to be known to both.

• Shall we go get some ice cream?

• I’m on a diet.

• Fine, a protein shake then?

Inference

• A lot of communication actually takes the form of inference, conclusions drawn from things unsaid. Assuming connections between sentences.• I walked into the room. The windows looked

out onto the bay.

• We know things about rooms. They have windows, often.

Schank and Frames

• No discussion of our reliance on background knowledge can avoid mentioning Roger Schank’s work almost 30 years ago trying to “teach computers semantics.”

• Schank et al. devised scripts to represent common situations, to form a backdrop for a conversation. The standard example is the restaurant script…

Restaurants• Actor goes to a restaurant• Actor is seated• Actor orders a meal from waiter.• Waiter brings meal to the actor• Actor eats the meal• Actor gives money to the restaurant• Actor leaves the restaurant.

• John went to a restaurant. The waiter gave John a menu. The waiter came to the table. John ordered a lobster. John was served quickly. John left a large tip.• What did John eat? (Lobster)• Who gave John the menu? (Waiter)• Who gave John the lobster? (Probably waiter)

Information packaging

• Information in utterances is generally “packaged” in a way that can take advantage of the background knowledge and inferences available. Information structure.

• One way this is accomplished by presuppositional items like the or stop, taking something in the context to be given.

Given vs. new• Much of what falls under information structure is the

division of given and new.• In the domain of noun phrases, for example, the

indefinite article a(n) is used to introduce a new referent, which can thereafter be referred to as given (with the).• A man walked into the room. The man carefully hung up his

coat and sat down.

• Sometimes this is modeled by analogy to file cards. A man creates a file card (a place to hold information about an individual referent), and then the man refers back to that file card.

Pronouns• Pronouns refer exclusively to given information

(although their reference can come from the physical context via pointing).

• Anaphora, indirect reference relation.• John ate a sandwich. He felt satisfied.

• Note: When working with syntax, anaphora are generally divided into two kinds (that have distinct conditions): anaphors (himself, herself, …), and (anaphoric) pronouns (him, her, …).• Mary saw her. Mary saw her reflection. Mary saw herself.

Focus and given/new

• Another way that information is marked as being new is through the use of focus (dividing the sentence into the focus and the presupposition, or the new and the given)

• HENRY cleaned the kitchen.Someone cleaned the kitchen.(It was) Henry.

• Henry CLEANED the kitchen.Henry did something to the kitchen.(It was) cleaning.

Contrast• Focus generally induces a kind of contrast.

• What did you get for your birthday?• I got a CHEESE GRATER.

• I thought John opposed that bill.• What? No, he VOTED for it.

• Many languages mark focus morphologically, with a focus marking particle. English tends to use stress, or clefts, pseudo-clefts like:• It was a cheese grater that I got.• What I got was a cheese grater.

Topic

• Often there is a sentence topic (separate from discourse topic). These too are often morphologically marked (Japanese wa), in English it can be paraphrased with As for.• As for birthday gifts, I got a cheese grater.• Me, I can’t figure him out.

• Topics are either given information or introduced as if they were.• This guy, he asked me for directions.• As for him, he couldn’t care less.

On file cards

• A woman with a small child came in• She[wa] ordered chicken-fried steak.• Next, a young man holding a tennis racket came in.• He[wa] handed her the racket and went to the bar to get a beer.• Another man and woman, who were late, came in.• It seemed (they) had been at a movie.

(Portner and Yabushita 1998)

• The woman who ordered chicken-fried steak left first.• ??The woman who the man had handed a racket to left first.

Focus and questions

• John did not introduce Bill to SUE.• John did not introduce BILL to Sue.

• Evoked questions

• Where were you at the time of the crime?• I was at HOME.• I was at HOME.• Evoked questions, a superquestion, and a strategy.

Conversational implicature

• Paul Grice: Inferences can be predicted by adopting a cooperative principle.

• The idea is that we can draw conclusions based on what is said in addition to making the assumption that the speaker is participating cooperatively.• How is Charles getting on in his job?• Oh quite well, I think. He likes his colleagues, and he hasn’t

been to prison yet.

• Grice identified several aspects of this cooperation, which he called maxims.

Gricean maxims• Quality: Be truthful.

• Do not say what you believe is false.• Do not say that for which you lack adequate evidence.

• Quantity: Be informative.• Make your contribution as informative as required.• Do not make your contribution more informative than required.

• Relation: Be relevant.• Make your contribution relevant.

• Manner: Be perspicuous.• Avoid ambiguity, obscurity.• Be brief, orderly

Conversational implicatures• Pat has two children.

• —I’m out of gas. —There’s a garage around the corner.

• —I’m out of gas. —There’s a tiger eating my lunch.

• The dinner was adequate. (In fact, it was great.)

• Mr. Smith always shows up to class on time and well-dressed.

• Ms. Smith produced a series of sounds that corresponded closely with the score of Home Sweet Home.

• Bill is a fine friend.

Entailment and informativeness

• I have a red sock I have a sock

• I have one sock I have two socks I have three socks I have four socks

• I have four socks is a stronger statement than I have one sock.

Focus sensitive adverbs

• John did not give a book to MARY.• John even gave a book to MARY.• John only gave a book to MARY.

• Informativeness:• John has a book.• John has two books.• John has twelve books.

“NPIs”

• I don’t have any socks.

• *I have any socks.

• Do you have any socks?

• If I had any socks, I wouldn’t be calling you.

• Any socks would be welcome.

• Pick any card.

• Every student with any socks is happy.

• *Every happy student has any socks.

Entailment• I have a red sock I have a sock.

• I don’t have a red sock I don’t have a sock• If I had a red sock, I wouldn’t be calling you

If I had a sock, I wouldn’t be calling you• A red sock would be welcome

A sock would be welcome• Pick a red sock Pick a sock• Every student with a red sock is happy

Every student with a sock is happy.

• I don’t have any socks. If I had any socks, I wouldn’t be calling you. Any sock would be welcome. Pick any sock.

red sockssocks

NPIs

• —Do you have dry socks?—I don’t have any socks.Downward entailing

• —Do you have potatoes?—Nope.—Not even bruised ones?—I don’t have any potatoes. Leave me alone.

• I don’t have even one sock. DE, stronger.• *I have even one sock. UE, not stronger.