Accommodating the dialogue plan

After an initial exchange for establishing contact the first thing that P says to the travel agent in our dialogue is:

$P: flyg ti paris
< flights to Paris >

This is again an ellipsis which on our analysis has to be interpreted as the answer to a question in order to have content. As no questions have been raised yet in the dialogue (apart from whether the participants have each other's attention) the travel agent cannot find the appropriate question on his plan. Furthermore, as this is the first indication of what the customer wants, the travel agent cannot have a plan with detailed questions. We assume that the travel agent has various plan types in his domain knowledge determining what kind of conversations he is able to have. E.g. he is able to book trips by various modes of travel, he is able to handle complaints, book hotels, rental cars etc. What he needs to do is take the customer's utterance and try to match it against questions in his plan types in his domain knowledge. When he finds a suitable match he will accommodate his plan, thereby providing a plan to ask relevant question for flights, e.g. when to travel?, what date? etc. Once he has accommodated this plan he can proceed as in the previous example. That is, he can accommodate the QUD with the relevant question and proceed with the interpretation of ellipsis in the normal fashion.

This example is interesting for a couple of reasons. It provides us with an example of ``recursive'' accommodation. The QUD needs to be accommodated, but in order to do this the dialogue plan needs to be accommodated. The other interesting aspect of this is that accommodating the dialogue plan in this way actually serves to drive the dialogue forward. That is, the mechanism by which the agent interprets this ellipsis, gives him a plan for a substantial part of the rest of the dialogue. This is a way of capturing the intuition that saying flights to Paris to a travel agent immediately makes a number of questions become relevant.