Towards a hierarchical extension of contextual bipolar queries

Abstract

We are concerned with the bipolar database queries in which the query is composed of a necessary (required) and optional (desired) part connected with a non-conventional aggregation operator “and pos-sibly”, combined with context, as, for instance, in the query “find houses which are cheap and – with respect to other houses in town – possibly close to a railroad station”. We deal with a multivalued logic based interpretation of bipolar queries. We assume that the human user, usually a database novice, tends to use general terms in the queries in natural language, which do not directly relate to attributes, and via a question and answer process these terms are “decoded” using a concept hierarchy that at the end involves terms directly related to attribute values. We propose a novel extension of our contextual hierarchical bipolar database query in which the original query is considered a level 0 query at the bottom of the precisiation hierarchy, then its required and optional parts are assumed to be bipolar queries themselves, with an account of context. This makes it possible to further precisiate the user’s intentions/preferences. A level 1 of precisiation is obtained, and the process is continued so far as it is necessary for the user to adequately reflect his/her intentions/preferences as to what is sought. The new concept is demonstrated on an intuitively appealing real estate example which will serve the role of both an illustration of the idea of our approach and of a real example.