Indexed Tree Matching with Complete Answer Representations

Abstract

. This paper picks up the Tree Matching approach to integrate the paradigm of structured documents into the field of Information Retrieval. The concept of Tree Matching is extended by the notion of complete answer representations (CARs), which makes it possible to avoid the combinatorial explosion in the number of solutions (and thus complexity). An algorithm is presented that combines a class of Tree Matching problems with index-based search and returns a CAR in linear time. 1 Introduction During the last years, considerable effort has been put into the integration of structured documents into the field of Information Retrieval. Various systems have been proposed, providing facilities to query a set of documents on structure and content level (see [NBY96] and [Loe94] for surveys). These queries provide the user with a powerful instrument: She may query for instance for all letters containing a subject line somehow related to the term "insurance". She can select out of a document pool..