On the relationship between user models and discourse models
Robin A Cohen · OLAC - Open Language Archives Community · 1988
The best way to summarize my view the relationship between user models and discourse models is that they are separate, related to each other. This paper will show why the two terms have completely distinct elements, and where the common ground between the two lies. It is also important to acknowledge at the outset that the two terms have not been well defined in the literature. For the discourse model, I am including everything that should be derived from an analysis discourse, to present a representation for the the discourse, useful in subsequent responses. In this sense, I focus on the interpretation a discourse from the point view one the conversants. I essentially include in the discourse all the components covered by the model Grosz and Sidner (1986). For the definition the user model, I also ground the discussion in the point view one conversant. The model is thus an analysis the other conversant (subsequently referred to as the speaker). The term user model is especially obscure, because in the context this journal it is confined to a derivation background knowledge and goals a user which influence the language used in the discourse. (One can use a similar term in the design graphical interfaces, for instance). The discourse model must thus contain the following key elements: an indication the the discourse and an organization the objects the real world mentioned in the discourse (to help anaphora resolution, for example). As soon as this kind history objects is included (covered in the model Grosz and Sidner (1986) by tracking attentional state and the objects currently in focus), there are elements that are not specifically attached to the user himself. The the discourse is essentially provided in two different ways. Which the actual utterances the discourse group together into logical segments is covered by the linguistic structure Grosz and Sidner (1986). Often clue words (such as but anyway) will indicate how to segment the utterances into logical segments, without concern for how individual utterances within that segment relate. In addition, there is an indication the intentional structure. Here, I would reinterpret slightly the term as used in Grosz and Sidner (1986) (see Cohen 1986). Intentional should indicate the intentional relations between, again, actual utterances. For instance, it is important to determine the cases where the goal underlying an utterance to the satisfaction of the goal underlying another utterance--e.g., getting the hearer to believe some proposition p contributes to the satisfaction getting the hearer to believe some proposition q (determined as dominance relations in Grosz and Sidner (1986). In this sense, my interpretation the derivation intentional agrees well with Wahlster's appeal for an incremental derivation the discourse model). I believe that the intentional is related to, not identical with, the plan the speaker underlying discourse. For one, the plan the speaker can be reconstructed at a different level detail than what is actually uttered. For an example, see Appendix 1. This leads me to where I feel the discourse model and user model relate. The plan the speaker underlying discourse is one part the user model and is related to the intentional the discourse. But there is more to the user model as well. There has been a good deal work on co-operative responses (e.g., Joshi et al. (1984)). Van Beek (van Beek and Cohen 1986, van Beek 1986) shows that goals and systemwide preferences a user can influence appropriate responses (e.g., preferring to take numerical analysis courses in a course advisor domain). It is thus important to include a model the user's goals (beyond an understanding the goal underlying each individual utterance, useful for the reconstruction the intentional structure). This kind