Dialogue

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Dialogue

• Ling 571
• Fei Xia
• Week 8 11/15/05

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Outline

• Properties of dialogues
• Dialogue acts
• Dialogue manager

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Properties of dialogue

• Turn-taking
• Grounding
• Implicature

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Turn-taking

• Overlapped speech less than 5.
• Little silence between turns either The speaker
  begin motor planning before the previous speaker
  finishes.
• Turn-taking rule
• If the current speaker selects A, A must speak.
• If the current speaker does not select the next
  speaker, any speaker can speak.
• If no one else takes the next turn, the current
  speaker may take the next turn.

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Turn-taking (cont)

• Adjacency pair two-part structures
• Question / Answer
• Greeting / Greeting
• Complement / downplayer
• Request / Grant
• Significant silence follows 1st part of an
  adjacency pair.

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Turn and utterance

• A single utterance may span several turns
• A I am leaving tomorrow
• B really?
• A right after my class.
• A turn may contain several utterances
• A Do you think it will work? Will John get mad
  at me? What if Mary does not like it?
• B Slow down.

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Grounding

• Speaker and Hearer must establish common ground.
• Examples
• Acknowledgement yeah, thats great
• Demonstration rephrase or collaboratively
  completing As utterance
• Request of repair Huh? What?
• .

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Conversational Implicature

• Example
• A What day in May did you want to travel?
• B I need to be there for a meeting that is from
  12th to 15th.
• Speakers expect hearers to draw certain
  inferences.
• (Grice, 1975) What enables hearers to draw these
  inferences is that conversation is guided by a
  set of maxims.

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Grices four maxims

• Maxim of Quantity Be exactly as informative as
  is required
• Make your contribution as informative as is
  required (for the current purposes of the
  exchange).
• Dont make your contribution more informative
  than is required.
• Ex There are three flights today.

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Grices maxims (cont)

• Maxim of Quality try to make your contribution
  one that is true
• Do not say what you believe to be false.
• Do not say that for which you lack adequate
  evidence
• Maxim of Relevance be relevant.
• Maxim of Manner be perspicuous
• Avoid obscurity of expression
• Avoid ambiguity
• Be brief
• Be orderly

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Grices maxims (cont)

• Maxim of Quantity
• Maxim of Quality
• Maxim of Relevance
• Maxim of Manner
• Do people actually follow the maxims?

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Properties of dialogue

• Turn-taking
• Overlapping speech
• Little silence
• Turn-taking rules
• Utterance segmentation
• Grounding acknowledgement, request of repair
• Implicature four axioms
• Case study Instant messaging

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Instant messaging

• Turn-taking
• More overlapping speech
• Longer silence
• Turn-taking rules
• More unsynchronized exchange
• One more level utterance, turn, message
• Grounding is more important.
• Implicature four axioms
• Discourse structure a tree?

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Outline

• Properties of dialogues
• Dialogue acts
• Dialogue manager

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Dialogue acts

• Austin (1962) three kinds of acts
• Locutionary act the act of uttering a string of
  words
• Illocutionary act (a.k.a. speech act) the act
  that the speaker performs in the utterance
• Perlocutionary act production of effects by
  means of the utterance.
• Searle (1975) five classes of speech acts

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DAMSL architecture

• DAMSL Dialogue Act Markup in Several Layers
• Forward looking function
• Statement
• Info-Request (e.g. Check)
• Influence-on-Addressee
• Influence-on-speaker (e.g., Offer, Commit)
• Conventional (e.g., Opening, Closing, Thanking)

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DAMSL (cont)

• Backward looking function
• Agreement Accept, Reject, Hold
• Answer
• Understanding
• Signal-non-understanding
• Signal-understanding Ack, Repeat-Rephrase,
• Tag set is hierarchical e.g., CHEK is a kind of
  INFO-REQUEST

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An example

• assert C I need to travel in May.
• info-req, A And, what day in May do you want
• Ack to travel?
• assert, C I need to be there for a meeting
• Answer on 15th.
• info-req, A And you are flying into what
  city?
• ack
• assert, C Seattle.
• Answer

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How to identify these acts?

• Examples
• Can you give me a list of flights from A to B?
• Its hot in here.
• Two models
• Inference model symbolic approach
• Cue model statistical approach

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Plan inference model

• Plan inference (PI) rules
• Action-Effect Rule if action X causes Y, and if
  H believes that S wants X to be done, then it is
  plausible that H believes that S wants Y to
  obtain.
• .
• Ex Can you give me a list of flights .?
• X asked me a question about whether I have the
  ability to give a list of flights.
• I assume that X is being cooperative in the
  conversation (in the Gricean sense) and that his
  utterance has some aim.
• X knows that I have the ability to give such a
  list, and there is no alternative reason why X
  should have a purely theoretical intereset in my
  list-giving ability.

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Can you give me a list of flights ?

1. Therefore Xs utterance probably has some
   ulterior illocutionary point. What can it be?
2. A preparatory condition for a directive is that
   the hearer have the ability to perform the
   directed action.
3. Therefore X has asked me a question about my
   preparedness for the action of giving X a list of
   flights.
4. Furthermore, X and I are in a conversational
   situation in which giving lists of flights is a
   common and expected activity.
5. Therefore, in the absence of any other plausible
   illocutionary act, X is probably requesting me to
   give him a list of flights.

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Cue-based model

• Cues
• Words and collocation Would you for request
• Prosody rising pitch for Yes-no question,
  stress, energy, .
• Conventional structure
• (1) A Do you want to see the movie?
• (2) B Yeah.
• (1) A John was very late last night. I was very
  mad at him,
• (2) B Yeah.

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Cue-based approach (cont)

• Treat it as a tagging problem.
• Given the evidence E, find a dialogue act
  sequence D, such that

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Cue-based approach (cont)
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Outline

• Properties of dialogues
• Dialogue acts
• Dialogue manager

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Dialogue Manager
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Where are dialogue systems used?

• Banks, Utility companies,
• Airline travel information systems
• Restaurant guides
• Telephone interfaces to emails or calendars
• Financial services buy/sell stocks
• Technology Apple, Dell, Microsoft,

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What does a dialogue system do?

• Understand humans utterance
• Reference resolution
• Dialogue act
• Humans intention
• Decide what to do the intended dialogue act
• Produce the utterance

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A dialogue system

• Homey Home monitoring through intelligent dialog
  system
• By Advanced Computation Lab (ACL), part of Cancer
  Research UK, Europe's largest independent cancer
  research organization.
• Demo local-demo

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Dialogue

• Patients Age? 42-yr and female.
• Jewish? No.
• Does the patient have cancer? Yes.
• What kind of cancer? Others.
• Bah bah is it correct? Yes.
• Age when diagnosed? 40 yrs
• Relatives with cancers her sister has breast
  cancer, her fathers mom has varying cancer
• Father has cancers? No
• Fathers sibling No
• Mother has cancer? No, but her mothers sibling
  has cancer.
• What kind of cancer? Other.
• Mothers parents have cancer? No.
• Bah bah , Is it correct? No, she was 41.
• Bah bah ..., is it correct? Yes.
• Two possibilities. Increase risk or population
  risk. I recommend increase risk. what do you
  advise?
• Why? Give reason.
• Is there evidence for population risk? No.

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Observation

• Can handle extra info
• H she was 42 and female.
• Follow-up questions
• H Her mothers sister has cancer
• S what kind of cancer?
• Reference solution
• S ., is it correct?
• H No, she was 41.
• S ..., is it correct?

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Observation (cont)

• Explicit batch confirmation and correction
  afterwards
• Mixed initiative
• S I recommend .. What do you advise?
• H Why do you recommend that?
• S Because .
• Inference
• 42 ? under 45
• fathers mother ?one of fathers parents

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Components of a dialogue system

• Speech recognizer
• Speech synthesizer
• Natural language generator
• IE to fill some templates
• Pronoun resolution
• Knowledge base medical ontology
• Dialogue manager

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Dialog management

• Goal determine how to respond to user utterance
• Answer user question
• Solicit information
• Confirm/Clarify user utterances
• Notify invalid answer
• Suggest alternatives
• Interface between user/language processing
  components and system knowledge base

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Initiative strategies

• System-initiative system always has control
• User-initiative user always has control
• Mixed-initiative control switches between user
  and system.

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Confirmation strategies

• Human I want to go to Seattle
• Explicit
• System did you say you want to go to Seattle?
• Implicit
• System what time did you want to leave
  Seattle?

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An example

• Human I want to go to Pittsburgh in May.
• Dialogue manager
• Turn holder system
• Intended speech acts Req-info, Ack, Clarify
• Discourse goal get-travel-info,
  create-travel-plan
• System And, what day in May did you want to
  travel?

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FSA-based system
No
What city are you leaving from?
Is-city(answer)
No
Where are you going?
Is-city(answer)
No
When would you like to leave?
Is-time(answer)
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Template-based approach

• Slots
• From_airport From what city are you leaving?
• To_airport Where are you going?
• Dep_time When would you like to leave?
• Arr_time
• Fare_class
• Airline
• One_way
• Nonstop
• Preferred_seat
• Food_preferrence

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Evaluation measures

• User satisfaction ask human to fill out
  questionnaires
• Were answers provided quickly enough?
• Was the system easy to use?
• Task completion success maximize success rate
• Percent of subtasks completed
• Correctness of each utterance
• Task completion cost minimize cost
• Completion time in turns or seconds
• Number of queries
• Number of system non-responses

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How good are automated systems?

• An article on the Seattle Times (11/6/05)
• How to outsmart automated phone systems?
• Shortcuts and tips
• Go to the website or use live-chat.
• Sometimes it is faster to not respond when
  prompted by an automated phone system, or pretend
  youre calling from a rotary-dial phone.

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Summary of Dialogue

• Properties of dialogues
• Turn-taking
• Grounding
• Implicatures
• Dialogue acts
• Types of dialogue acts
• Identifying dialogue acts inference-based,
  cue-based
• Dialogue manager