Accenting and Given/New Status

1. Accenting and Given/New Status Julia Hirschberg CS 4706

2. Issues • What discourse structures are important in processing? • What are the intonational cues to these structures? • Can listeners readily attend to these cues? On-line? • How do they incorporate intonational information in their interpretations? What other information do they use?

3. Defining Given/New • Halliday ‘67: • Given: Recoverable from some form of context • New: Not recoverable • Chafe ’74 ’76: • Given: what S believes is in H’s consciousness • New: what S believes is not… • “Chafe-givenness” Yesterday I had my class disrupted by a bulldog/dog. I’m beginning to dislike dogs/bulldogs. • But not vice versa….

4. Why do we care about the given/new distinction? • Building a model of the discourse • What do S and H believe to be true? • What is in their consciousness now? • What is ‘grounded’? • Speech technologies • TTS: Given information is often deaccented while new information is usually accented …but • ASR...

5. Prince ’81: A Given/New Taxonomy • Text as set of instructions from S to H on how to construct a discourse model • Model includes discourse entities, attributes, and links between entities • Discourse entities: individuals, classes, exemplars, substances, concepts (NPs) • Entities as ‘hooks’ on which to hang attributes (Webber ’78) • Entities when first introduced are new

6. Brand-new (H must create a new entity) I saw a unicorn today. • Unused (H already knows of this entity) I saw your roommate today. • Evoked entities are old -- already in the discourse • Textually evoked The unicorn was eating a muffin. • Situationally evoked That bus was going too fast! • Inferables • Containing

7. I bought a pair of socks. One of them had a hole in it. • Non-containing I bought a new car. One of the tires is already flat.

8. Prince ‘92 • Definiteness: subject NPs tend to be syntactically definite and old • Indefiniteness: object NPs tend to be indefinite and new I saw a black cat yesterday. The cat looked hungry. • Definite articles, demonstratives, possessives, personal pronouns, proper nouns, quantifiers like all, every signal definiteness • Indefinite articles, quantifiers like some, any, one signal indefiniteness

9. But…. This guy came into the room. There were the usual subjects at the bar.

10. What’s wrong with a Hearer-centric model of given/new? • Hearer-centric information status: • Given: what S believes H has in his/her consciousness • New: what S believes H does not have in his/her consciousness • But discourse entities may also be given and new wrt the current discourse • Discourse-old: already evoked in the discourse • Discourse-new: not evoked

11. Hearer-new --> Discourse-new (unless…?) • Discourse-new --> ? • Hearer-old --> ? • Discourse-old --> Hearer-old (unless….?) • What does this new distinction buy us? • A way to explain definiteness/indefiniteness in terms of Hearer status only • More fine-grained distinctions to explain why items are accented or deaccented

12. Inferrables: H-old, H-new, D-old,D-new • Entities S may believe H can infer based upon a previously evoked discourse entity A bus plowed into a store on Broadway. The driver emerged without a scratch. ?The bumper sticker read “How’s my driving?”. *The coins spilled everywhere.

13. Containing Inferrables • The entity that evokes the inferable is mentioned at the same time as the inferable The tires of my car were all flat. The fingers on her right hand turned blue.

14. Empirical Analysis (Prince ‘92) • What regularities can be observed for subjects? • Definite/indefinite • Hearer-old? Discourse-old? • Results: • D-old NPs tend to be subjects • D-old pronouns more likely to be subjects than other D-old NPs • D-old non-pronouns+Inferrables seem to pattern together

15. Discourse-old predicts subjecthood better than Hearer-old status or definiteness

16. How does this help us in analyzing/generating a discourse? • Analysis: • How can we identify sentence topics? • How can we decide what is in S and H’s discourse models? What would this tell us about what they know? Believe? • Generation: • How do we produce natural-sounding sentences? • How easy is this to do? For humans? Machines?

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18. Intonational marking of given/new • Pitch accents can cue given/new: Halliday (1967), Brown (1983), Terken (1984) • Hirschberg & Pierrehumbert (1986) relate given/new and accentuation to G&S’s model of global salience, accounting for ‘exceptions’: • deacc of entities in non-immed global focus • deacc of entities in sister DS, see Davis & Hirschberg (1988), Nakatani (1997) • accentuation of re-introduced given entities

19. Brown ‘83: How does accent related to given/new? • Speech elicitation in lab • Scottish English • Prince ‘81 derived categories • Results: • Brand-new information accented • Note: new entity/old expression • Inferable information accented • Evoked information deaccented

20. Bard’99: Givenness, deaccenting and intelligibility • Speech elicited in lab • Glasgow English Map Task • Given: repeated mention (within dialogue vs. across dialogue) • Does structural similarity --> deaccenting --> less intelligibility (Terken & Hirschberg ‘94) • Weird definition of deaccenting (includes difference in boundary tone)

21. So, do lab experiments generalize? • Results: • Deaccenting rare in repeated mentions (within and across dialogues) • Second mentions less intelligible whether deaccented or not (tho more change when deaccented) • Structural difference doesn’t account for deaccenting • But same structure repetitions rare

22. Intonation in processing information status • Are listeners sensitive to intonational correlates of information status? • Evidence that ‘appropriate’ accentuation facilitates comprehension: • Birch & Clifton (1995): appropriateness speeds makes-sense judgments in Q&A pairs • Bock & Mazzella (1983): comprehension time of denial-counterassertion pairs • Davidson (2001): phoneme-monitoring in denial-counterassertion pairs • Terken & Nooteboom (1987), Nooteboom & Kruyt (1987): verification latencies of target words

23. Intonational cues in on-line processing • Dahan et al. (2002): accentuation effects referential interpretation even at very early stages of processing • Used eye-tracking to monitor listeners’ fixations on pictured entities as they heard instructions to manipulate these entities on computer screen • Examined moment-by-moment recognition of accented vs. unaccented words which share a primary-stressed initial syllable (e.g. candy/candle).

24. = candle = candy = candy = candle Dahan et al. (2002) • Example discourse: “Put the candy below the triangle. Now put the CANDLE above the square.” pred. fixation utt 1utt 2 <candle> Now put the [kæn] ... <candle> Now put the [kæn] ... <candy> Now put the [kæn] ... <candy> Now put the [kæn] ...

25. candle candy candle-CANDLE condition [From Dahan et al. (2002)] • Competition from “candy” upon hearing accented [kæn]. • Accentuation is used by listeners to process discourse representations on-line, as a word is unfolding.

26. Accent, Given/New, and Grammatical Function • Given/new interacts with property-sharing constraints to determine the distribution of accents in discourse. • Terken & Hirschberg (1994): prior mention and grammatical function --> deaccenting • Dahan et al ‘02 also examine conditions in which the antecedent and target did not share grammatical role: “Put the necklace below the candle. Now put the CANDLE above the square.” • NO competitor effects (i.e. looks to “candy” upon hearing accented [kæn])

27. [From Dahan et al. (2002)] No competitor effects in this condition! Here, accent serves to cue shift in “focus”. [See also Terken & Hirschberg (1994)] • “Put the necklace below the candle. Now put the CANDLE above the square.” • Prediction: “candle” is given  competition from “candy” upon hearing accented [kæn].

28. Grammatical Role or Syntactic parallelism? • Dahan et al.’s and Terken & Hirschberg’s data confound grammatical role with syntactic parallelism • Venditti et al ‘02,’03: syntactic parallelism (NOT just persistence of grammatical role) affects interpretation of nuclear-accented pronouns John hit Bill and then HE ... hit George. (N2 pref) ... ran away. (less N2 pref) • N2 pref when syntatically parallel clauses

29. Future directions • Processing in dynamic models of attention and discourse salience • Property-sharing, parallelism, and other interacting constraints on accentuation • Time course of integration of intonational information • Cross-linguistic perspectives on intonation and discourse processing • Role of ambiguity ‘awareness’ in experimental designs

30. Next Week • Read ASR overview • Go to Sameer’s lab on March 24 to get help building a TTS system or using a speech recognizer