Linguistic Variation in Information Retrieval and Filtering

In this paper, a natural language approach to Information Retrieval (IR) and Information Filtering (IF) is described. Rather than keywords, noun-phrases are used for both document description and as query language, resulting in a marked improvement of retrieval precision. Recall then can be enhanced by applying normalization to the noun-phrases and some other constructions. This new approach is incorporated in the Information Filtering Project Profile. The overall structure of the Profile project is described, focusing especially on the Parsing Engine involved in the natural language processing. Effectiveness and efficiency issues are elaborated concerning the Parsing Engine. The major contributions of this research include properties of grammars and parsers specialized in IR/IF (properties such as coverage, robustness, efficiency, ambiguity), normalization of noun-phrases, and similarity measures of noun-phrases. Dept. of Information Systems, Faculty of Mathematics and Computing Sc..