We define dialogue moves as updates to information states directly associated with utterances. If you take a dialogue or information update perspective on Lewis' notion of accommodation, it corresponds to moves that are tacit (i.e. not associated with an utterance). Tacit moves can be seen as applications of update rules, which specify how the information state should be updated given that certain preconditions hold. Tacit moves could also be called ``internal'' or ``inference'' moves. The motivation for thinking in terms of accommodation has to do with generality. We could associate expressions which introduce a presupposition as being ambiguous between a presuppositional reading and a similar reading where what is the presupposition is part of what is asserted. For example, an utterance of ``The king of France is bald'' can either be understood as an assertion of that sentence and a presupposition that there is a king of France or as an assertion of the sentence ``There is a king of France and he is bald''. However, if we assume an additional tacit accommodation move before the integration of the information expressed by the utterance then we can say that the utterance always has the same interpretation.
In a similar way we can simplify our dialogue move analysis by extending the use of tacit moves so that the updates to the information state normally associated with a dialogue move are actually carried out by tacit moves. One argument for doing this is that very few (if any) effects of a move are guaranteed as a consequence of performing the move; rather, the actual resulting updates depend on reasoning by the addressed participant. Thus, we define an update rule intergrateLatestMove which, given that the latest move was accepted by the system, performs the appropriate update operations. The updates for a move are different depending on whether it was the system or the user who made the move, but the same module is used in both cases.