Treffer: TREC-5 experiments at Dublin City University : Query space reduction, Spanish & character shape encoding

In this paper we describe work done as part of the TREC-5 benchmarking exercise by a team from Dublin City University. In TREC-5 we had three activities as follows: 1) Our ad hoc submissions employ Query Space Reduction techniques which attempt to minimise the amount of data processed by an IR search engine during the retrieval process. We submitted four runs for evaluation, two automatic and two manual with one automatic run and one manual run employing our Query Space Reduction techniques. The paper reports our findings in terms of retrieval effectiveness and also in terms of the savings we make in execution time. 2) Our submission to the multi-lingual track (Spanish) in TREC-5 involves evaluating the performance of a new stemming algorithm for Spanish developed by Martin Porter. We submitted threee runs for evaluation, two automatic, and one manual, involving a manual expansion from retrieved documents. 3) Character shape coding (CSC) is a technique for representing scanned text using a much reduced alphabet. It has been developed by Larry Spitz of Daimler Benz as an alternative to full-scale OCR for paper documents. Some of our TREC-5 experiments have started evaluating the performance of a CSC representation of scanned documents for information retrieval and this paper outlines our future work in this area.