Cooperative Query Answering via Type Abstraction Hierarchy

Abstract

Cooperative query answering consists of analyzing the intent of the query and providing generalized, neighborhood or associated information relevant to the query. The key issues to accomplish cooperative query answering consist of supporting different knowledge representations at different abstract levels and providing inference between these levels. In this paper the Type Abstraction Hierarchy is proposed which is characterized by dealing with subtyping from subsumption, composition, and also abstraction views. Based on the type abstraction feature provided by this model, an inference technique for cooperative query answering is developed. Such an inference is performed by abstracting and refining the goal to generalize and specialize the query scope and to derive relevant answers with different generality, coverage, and approximation, or to link related subjects at certain levels by using different representations of knowledge given at different levels. A prototype system has been implemented at UCLA that demonstrates the use of this approach for such decision making and problem solving applications as conceptual query processing, neighborhood inference, and subject association.