Jurafsky & Martin Speech and Language Processing Ch 19
- why dialog is different
- representing and interpreting dialog acts
- dialogue structure'and coherence
- dialogue system architecture
- dialogue management and, other modules
- case study of Why-Atlas'tutoring system and
- NLP in industry .
Dialogue and Conversational Agents
- "Conversation or dialogue is the most fundamental and-specially privileged arena of language."
- What makes dialogue different?
- Speech act representation and interpretation.
- Approaches to Coherence and structure.
Example Conversational Agents
- Phone system for flight reservations
- Why2 Physics Tutor
- NJFUN ---> is a real-tim spoken dialogue system that provided users with information about things to do in New Jersey. NJFUN is built using an internal platformal for spoken dialogue systems. NJFUN uses a speech reccognizer with stochastic language models trained from example user utterances, and a TTS system based on concatenative diphthone synthesis. Its database is populated from the NJ-online webpage to contain information about activities. NJFUN indexes this database using three attributes: activity type, location and time of day.
Turns and Utterances
- Dialogue is characterized by turn-taking.
- Speakers know how to take turns (who should talk next, and when they should talk)
- little overlap (around 5% in English - although depends on the domain)
- not much silence between turns either.
- Conversational Analysis provides a socio-linguitic approach to turn-taking (e.g. Sacks et al)
- Transition-relevance places are where the structure of the language allows speaker shifts to occur.
- Turn-Taking Rule (simplified): At each transition-relevance place of each turn:
- If during this turn current speaker has selected A as the next speaker, then A must speak next.
- If current speaker does not select the next speaker, any other speaker may take the next turn.
- If no one else takes the next turn, the current speaker may take the next turn.
- Transition-relevance places are typically at utterance boundaries.
- Spoken utterances are typically shorter, contain more pronouns, have repairs compared to written sentences.
- Many theories take the utterance as the primitive unit, but utterances are difficult to segment.
- a single utterances may occur across several turns.
- A: We've go you on USAir flight 99.
- B: Yep
- A: leaving on December 1.
- Multiple utterances may occur in a single turn.
- We've got you on USAir flight 99 leaving on December 1. Do you need a rental car?
- Linguistic boundary clues include words, ngrams, prosody.
- GREETING GREETING
- QUESTION ANSWER
- COMPLIMENT DOWNPLAYER
- REQUEST GRANT
- A; Is there something bothering you or not? (1.0)
- A: Yes or no? (1.5)
- A: Eh?
- B: No.