Issues in Multiparty Dialogues

1. Issues in Multiparty Dialogues Ronak Patel

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

3. Current Systems

4. 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 )

5. Problems What patterns of information exchanges do conversational participants form? Patterns of initiative taking Data Collection

6. 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 -> B (A want C listen) D hear the Q without A’s intention. Listener is in –context or out of context (interpret utterance quite differently)

7. 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

8. 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.

9. 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. .

10. 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.

11. 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

12. 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)

13. 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…

14. 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

15. 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 )

16. 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.

17. Problems Scene: Three party dialogues using the task of scheduling meetings.

18. Discussion Structure

19. 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)

20. 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.

21. Thank You