The Effect of Syntactic Phrase Indexing on Retrieval Performance for Dutch Texts

In this paper we describe an experiment with syntactic phrase indexing for Dutch texts. We compare different choices for combining terms to form head-modifier pairs and we also investigate the effect of adding none, one, or all constituent parts of the pair as a separate index term. The results of our experiments show that using head-modifier pairs as index terms can improve both recall and precision significantly but only if all constituent parts are also added separately. We found that using both Noun-Adjective and Noun-Noun head-modifier pairs produced the best results.