“Downstepped contours in the given/new distinction” Agustín Gravano Spoken Language Processing...

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“Downstepped contours in the given/new distinction”

Agustín Gravano

Spoken Language Processing Group

Columbia University, New York

On the Role of Prosody in Structuring DiscourseOctober 5, 2005 - Berlin, Germany

Participants in this project

Columbia University (New York)Julia HirschbergStefan BenusAgustín Gravano

Northwestern University (Chicago)Gregory WardElisa Sneed

Agustín Gravano - Columbia University

1. Introductiona) ToBI

b) Discourse structure (Grosz & Sidner ’86)

c) Information status (Prince ’92)

d) Meaning of intonational contours

e) The downstepped contours

2. Boston Directions Corpusa) Description of the corpus

b) Downstep and discourse structure

c) Downstep and information status

3. Games Projecta) Description of the corpus

b) Ongoing and future research

To(nes and)B(reak)I(ndices)• Prosody annotation convention.

• Two tones: H and L, which may be combined (e.g. H+L)

• Devised originally for Standard American English, but ToBI standards also proposed for Japanese, German, Italian, Spanish, British, Australian English,....

• 4 tiers:

– orthographic tier: words

– break-index tier: degrees of junction

– tonal tier: pitch accents, phrase accents, boundary tones

– miscellaneous tier: disfluencies, non-speech sounds, etc.

Discourse Structure (G&S ’86)

• Series of discourse segments, defined in terms of the speaker’s intentions: the discourse segment purpose (DSP).

• Let a, b: DSP,– a satisfaction-precedes b

iff a must first be achieved in order for b to succeed;– a dominates b

iff fulfilling b partly fulfills a.

Barbara Grosz & Candace Sidner, 1986. “Attention, intentions, and the structure of discourse.” Computational Linguistics 12(3): 175-204.

Information Status (Prince ’92)

Ellen Prince, 1992. “The ZPG letter: Subjects, definiteness, and information-status.” In Discourse Description: Diverse Analyses of a Fund Raising Text, S. Thompson & W. Mann (eds.), 295-325, Philadelphia: John Benjamins B.V.

Discourse {• Given

• New

Hearer{• Given• Inferrable• New

Multiple “meanings” of intonational contours

• “Declarative” contours (H* L- L%)– Statements– Wh-questions

• Rise-fall-rise contours (L*+H L- H%)– Uncertainty– Incredulity

• H* Downstepped contours (H* (!H*)+ L- (L%|H%)?)– Topic beginnings or endings?– “Given” information?

Example: H* !H* !H* !H* L-H%

Understanding the multiple uses of contours is useful and interesting

• In most TTS systems– ‘Standard’ declarative (H* L- L%) contour

over-used – ‘Given’ information deaccented too often

• The H* (!H*)+ L- (L%|H%)? contours might be used instead, if they are appropriate

H* (!H*)+ L- (L%|H%)? in Standard American English

• Topic structure markers (Pierrehumbert & Hirschberg ’90)– Beginning and ending of topics– Professorial tone

• Givenness (Hirschberg & Pierrehumbert ’86, Ladd ’96, Dahan et al ’02)– “This material should already be familiar to you.”– Alternates with deaccenting – when?

1. Introductiona) ToBi

Boston Directions Corpus

• 4 speakers

• 9 increasingly complex direction-giving tasks

• Spontaneous speech transcribed and speakers returned and read

• ~67m spon; ~50m read

firstenter the Harvard Square T stopand buy a tokenthenproceed to get on theinboundumRed Lineuh subwayandtake the subwayfrom Harvard Squareto Central Squareand then to Kendall Squarethen get off the T

Boston Directions Corpus

BDC - Discourse Structure

BDC - Information Status

Discourse Given

BDC - Information Status

Hearer Given Hearer Inferrable

BDC - DS Contours

Downstep and Discourse Structure

• Distribution of use of DS contours for signaling discourse structure?

• How frequently is discourse structure conveyed using DS contours?

• Does this differ by speaking style (read vs. spontaneous speech)?

• Is there notable speaker variation in either of these?

Use of DS contoursfor discourse position

Contour Seg Beg Seg Final Total

H* (!H*)+ L- (L%,H%)?

88 (18%) 196 (40%) 488

Contour Seg Beg Seg Final Total

H* (!H*)+ L- (L%,H%)?

131 (29%) 195 (43%) 451

Spontaneous:

Discourse position conveyedusing DS contours

Contour Seg Beg Seg Final

H* (!H*)+ L- (L%,H%)?

88 (11%) 196 (28%)

Total 825 (100%) 693 (100%)

Contour Seg Beg Seg Final

H* (!H*)+ L- (L%,H%)?

131 (18%) 195 (31%)

Total 721 (100%) 635 (100%)

Spontaneous:

Speaker variability

• We found high variability (both in spontaneous and read speech) in:– Overall use of DS contours– Distribution of use of DS contours– Frequency with which discourse structure is

conveyed using DS contours

• Only exception:– Speakers employ ~40% or more of their DS

contours over Segment Final phrases.

• Are DS contours used over given information, alternating with a deaccenting strategy?

• If so, when do speakers choose one strategy over another?

• Information status in the BDC data:– at the NP level (both discourse g/n and hearer g/i/n

status),– at the word level (discourse g/n status for individual

lexical items).

• Smaller corpus: only spontaneous data labeled.

Downstep andInformation Status

Downstep andInformation StatusHearer Given

Hearer Inferrable

Hearer New

Discourse

Discourse New

All deacc 52 (5%) 6 (2%) 3 (2%) 46 (8%) 15 (2%)

DS416 (39%)

200 (49%) 58 (45%) 261 (44%) 413 (44%)

Other DS 48 (5%) 25 (6%) 12 (9%) 32 (5%) 53 (6%)

Other 540 (51%) 175 (43%) 57 (44%) 257 (43%) 469 (49%)

Total 1056 (100%) 406 (100%) 130 (100%) 596 (100%) 950 (100%)

Spontaneous productions only.

Downstep and Information StatusHearer Given

Hearer Inferrable

Hearer New

Discourse

Discourse New

All deacc 45 (8%) 3 (4%) 0 (0%) 44 (8%) 4 (4%)

DS260 (45%)

38 (54%) 3 (33%) 251 (45%) 50 (52%)

Other DS 28 (5%) 2 (3%) 2 (22%) 28 (5%) 4 (4%)

Other 244 (42%) 27 (39%) 4 (44%) 237 (42%) 38 (40%)

Total 577 (100%) 70 (100%) 9 (100%) 560 (100%) 96 (100%)

Spon - Only NPs for which all lexical elements are Given.

• DS contours clearly dominate Hearer-Inferrables.

• DS contours are commonly used over Given information.

• Little evidence from this study that information status is a major predictor of the use of DS contours: equally likely to be used over New NPs.

Downstep andInformation Status

• Elicit a corpus of spontaneous dialogue containing:– given and new NPs– topic segmentation data

Games Project - Goal

Games Project - Design

Session:– 3 collaborative computer games.– 2 players, each with an electronic game board.– Unrestricted speech.– No visual contact between subjects.– Subjects were paid a fixed amount of money, plus

a bonus based on their performance.– Each subject participated in 2 sessions with

different partners and on different days.

PLAYER 1“DESCRIBER”

PLAYER 2“SEARCHER”

Game # 1

Game # 2

Game # 3

• Study the relation between the choice of intonational contours and:– givenness status of NPs– syntactic position of NPs– complexity of NPs– proportion of given lexical elements in new NPs– discourse structure

• How?– Games 1 & 2:

• Cards have increasingly more features, increasing the complexity of NPs

• Some features appear more frequently, becoming “given”.• Features appear in different sizes.

– Game 3: • Subject blinking/target image.• Objects images surrounding the target image.

• Pretests

Games Project - Corpus

Corpus: – Recorded in a sound-proof booth at Columbia’s

Speech Lab in October 2004.– 12 sessions.– ~20 hours of spontaneous speech.– Fluent dialogues, each game with very different

characteristics. – All dialogues have already been transcribed.– Currently doing ToBI labeling.

• Ongoing studies– Discourse Markers (okay, mm-hm, yeah, etc.)– Turn-taking– Laughter

• Future studies– Use of the downstepped contour with respect to

discourse structure and info status.– Evolution of the description of lexical entities.– Disfluencies (false repairs, self-repairs, etc.)– …

Games Project - Studies

“Downstepped contours in the given/new distinction”

Agustín Gravano

Spoken Language Processing Group

Columbia University, New York

On the Role of Prosody in Structuring DiscourseOctober 5, 2005 - Berlin, Germany

“Downstepped contours in the given/new distinction” Agustín Gravano Spoken Language Processing...

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