Issues in Multiparty Dialogues

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Issues in Multiparty Dialogues

• Ronak Patel

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Current Trend

• Only two-party case (a person and a Dialog system
• Multi party (more than two persons Ex. Classroom
  , group meeting )

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Current Systems
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Issues

• Participant Roles (Who is who case, contains both
  local roles that shift during the conversation,
  such as speaker and hearer etc.)
• Interaction Management (Who speaks when, what is
  the topic under discussion, what communicative
  channels are used )
• Grounding and Obligations (What are common
  beliefs a promise, acknowledgment, or agreement
  (as a contract) that binds one to a specific
  performance )

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Problems

• What patterns of information exchanges do
  conversational participants form?
• Patterns of initiative taking
• Data Collection

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Participant Roles

• Conversational Roles
• In two party scenario basic roles of speaker and
  listener/addressee
• In multiparty scenario issues of Who receive an
  utterance and who is it address to
• Example A -gt B (A want C listen) D hear the Q
  without As intention.
• Listener is in context or out of context
  (interpret utterance quite differently)

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Participant Roles

• Speaker Identification
• In two party scenario not big deal (any speech
  that does not come from oneself must come from
  the other participant)
• In multiparty scenario microphone arrays can
  localize the position of the speech, and give us
  clue of who is the speaker

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Participant Roles

• Addressee Recognition
• In two party not big deal (whoever is not
  speaking)
• In multiparty scenario we must separate hearers
  and addresses
• Hearer can be found by properties like volume
  level of speech, distance etc
• Addressee A speaker directly indicate either
  by name or role also context can also work as
  clue in this case. Eg. Who had previously spoken
  or been addressed.

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Participant Roles

• Other Participant Roles
• Other than conversational roles, one can have
  specific task roles, relating participant to
  particular task.
• Like agent who is authorized to tell team member
  to carry out the task, one can have agent as
  guards also, making sure that task is not
  performed.
• In multiparty this roles become more complex
  imagine a court room environment.
• Social Roles - status (superior, equal) ,
  closeness (friend, colleague) will influence the
  kinds of interaction allowed. .

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Interaction Management

• Turn Management
• Deals with Q of when to speak and when to stop?
• Depends on languages cultures.
• One way is that speaker should give some verbal
  or non-verbal signals of continuation or
  termination.
• But in Multiparty its more complex
• as more agents more competition of taking turn
  more actions possible
• Speaker suggest the next one , if not then than
  it will be free competition for the floor.
• Likelihood of someone speaking decays with the no
  of turn in the discussion since he last spoke.

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Interaction Management

• Channel Management
• Uni-model communication systems (phone) Channel
  Management Turn Management
• In multi-channel system issue of which channel to
  use for which content, also timing of
  contribution.
• Channels can be using same (radio with different
  frequencies) or different modalities (speech for
  communication and video for attention and
  understanding)
• In multiparty dialog system we can use multiple
  main-channels e.g., one per topic, one per
  conversation

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Interaction Management

• Thread/Conversation Management
• Concerns what is being communicated (which topic
  discussed when, how to organize the progression
  of topic)
• Stack based topic organization a traditional
  way
• multiple conversation is more complex
• One solution is to have Multiple conversation
  Models.
• Problem might arrive when multiple conversations
  are not completely independent. (e.g., share
  participant)
• Problem become more worse with multiple
  participants and multiple conversations which may
  share participants.
• Solution is to use number of relationships
  (e.g., addressee and conversation , topics and
  conversations)

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Interaction Management

• Initiative Management
• Concerns Which agent is currently setting the
  agenda for topics.
• Two-party dialogue system are either
  user-initiative or system-initiative
• Mixed-initiative allows user and system both to
  take the initiative at different points.
• Cross-initiative, where a responder does not take
  initiative herself, but redirects it to a third
  party
• Cross-conversation initiative, where one
  conversation being dependent on another

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Interaction Management

• Attention Management
• Mostly assumed to be present (Takes binary
  value).
• In multiparty situations more detailed model
  required
• Can summon others into new or existing
  conversation.
• Can model which conversation each participant is
  attending to

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Grounding Obligation

• Grounding
• Process of adding to the common ground between
  participants in conversation.
• In multiparty situations which model to use is
  less clear
• One way is to allow any of the addressee to
  acknowledge for the contents to be considered
  grounded (Problem some agents did not in fact
  understand)
• Another way is to require evidence of
  understanding from each addressee (its
  unrealistic)
• Middle-Grounding is required.
• Grounding across conversations (A ask Q to B B
  ask same Q to C , A has evidence B has understood
  Q , even B has not responded A )

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Grounding Obligation

• Obligation
• Requests or Q can be treated as obligation
• In presence of multiple addresses, its not clear
  what the status of these obligations, Does every
  addresses have a personal obligation? etc
• Issue of transfer of obligation (Refer to
  previous Example)
• One Model is to use obligation as motivation
  (track obligations and then use these to motivate
  performing answers)
• Another model is to use dialogue structural
  considerations as Questions Under Discussion
  (QUD) , which represents information about what
  would count as an answer, while obligations
  represent who should/must answer.

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Problems

• Scene Three party dialogues using the task of
  scheduling meetings.

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Discussion Structure
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Problems

• The conclusion here is that two-party
  interactions are dominant in three-party
  dialogues.
• Initiative taking behavior is more clearly
  observed in three-party dialogues than those in
  two-party dialogues. (emergence of an
  initiative-taker or a chair person)
• Collecting Data in naturalist setting is
  difficult and expensive. (commitment to the task)

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Conclusions

• Treat multiparty conversation as a set of pairs
  of two-party models
• Simple use existing models
• Less satisfaction
• Move beyond the two party case ,helps to
  arbitrate between the multiple interactions.
• Bit more complex
• Some cases we can see two-party dialogues as a
  special simple case of multiparty dialogue.

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Thank You