Annotation-based Document Retrieval with Four-Valued Probabilistic Datalog

Abstract

The COLLATE system (collaboratory for annotation, in- dexing and retrieval of digitized historical archive material) provides film researchers with a collaborative environment in which historic documents about European films can be analysed, interpreted and discussed, using nested annota- tions and discourse structure relations among them. Anno- tations are metadata, and annotation threads form a hyper- text containing positive and negative links, constituting a certain kind of context exploitable for document retrieval. In this paper, we discuss a solution for using annotations for information retrieval. To exploit annotation threads which consist of nested annotations and typed links between them, an annotation-based retrieval approach should have to cope with negative and contradictory statements. The nested annotation retrieval approach (NARA) is an approach ad- dressing these issues. Based on this, we present NARAlog, an implementation using four-valued probabilistic datalog (FVPD), able to perform an in-depth analysis of annotation threads and to deal with contradictory statements.