BIPOLARITY IN CASE-BASED QUERYING

The user is not always able to easily express a request by expressing restrictions on attribute domains, even in a flexible way, these restrictions being then conjunctively combined. It may be more convenient for him to express what the user is looking for from prototypical examples, still keeping the idea of positive and negative requirements.

Suppose that, as in the system described in de Calmès, Dubois, Hüllermeier, Prade, and Sèdes (2002), the user is looking for some houses to let, described in a database. One may think of providing the user with typical examples of existing houses stored in the base, which are representative of different categories. The system may also propose a small set of (maybe fictitious, but realistic) houses to the user that are well-contrasted on the attributes of interest. We may also, more simply, assume that examples of houses the user likes, or dislikes, are provided by this user, referring to existing already experienced cases, if any (i.e., houses rent in the past, in our example).