BackChannelCommunication.pptVIP

Back Channel Communication Antoine Raux Dialogs on Dialogs 02/25/2005 Outline From Back Channel to backchannels Function of the Back Channel Characteristics of the Back Channel The Back Channel in Spoken Dialogue Systems From back channel… 70s: Conversation Analysts attempt to describe systematic rules for turn-taking management Goal: minimize gaps and overlaps between speakers BUT many overlaps in natural speech E.g.: “mm-hmm”, “okay”, “yeah”… “Back channel” (Yngve 1970): Parallel channel for communication (Duncan 1972) “Back channel communication does not constitute a turn or a claim for a turn” But it “may participate in a variety of communication functions, including the regulation of speaking turns.” …to backchannels “Backchannel”: listener-produced signal such as “mm-hmm”, “yeah”…(“To backchannel”: to produce such signals) Does not imply the will to take the turn Implies some form of acknowledgment (in general) Front vs Back Channel Front-channel cues to back-channel signals Koiso et al (1998) Analyze the relationship between different syntactic and prosodic features and the occurrence of backchannels Koiso et al (Methodology) Data: 8 dialogs from Japanese Map Task corpus: replica of the Edinburgh MT Face-to-face and speech only (no difference) Features Syntactic: POS Duration of last mora (normal/long/short) F0 pattern of last mora (flat-fall, rise…) Peak F0 (low/high) Energy pattern (late-decr, decr, no-decr) Peak energy (low/high) Koiso et al (Results) Frequency of feature values Koiso et al (Results) Decision Tree analysis Compare the loss in performance by not using each feature POS: single best feature Prosodic features altogether: as good as POS Koiso et al (Discussion) Some POS strongly inhibit BC Individual prosodic features are not good indicators of BC occurrence BC occurrence is conditioned by both POS and prosody (as a whole) What about other languages? What about BC overlapping with speech? BC cues in English and Japanese Ward and Tsukahar