# Variable−Strength Conditional Preferences for Ranking Objects in Ontologies

*Thomas Lukasiewicz and Jörg Schellhase*

### Abstract

We introduce conditional preference bases as a means for ranking objects in ontologies. Conditional preference bases consist of a description logic knowledge base and a finite set of variable-strength conditional preferences. They are inspired by Goldszmidt and Pearl's approach to default reasoning from conditional knowledge bases in System Z+. We define a notion of consistency for conditional preference bases, and show how consistent conditional preference bases can be used for ranking objects in ontologies. We also provide algorithms for computing the rankings. To give evidence of the usefulness of this approach in practice, we describe an application in the area of literature search.

Book Title

Proceedings of the 3rd European Semantic Web Conference‚ ESWC 2006‚ Budva‚ Montenegro‚ June 11−14‚ 2006

Editor

York Sure and John Domingue

ISBN

3−540−34544−2

Pages

288−302

Publisher

Springer

Series

Lecture Notes in Computer Science

Volume

4011

Year

2006