A comparison of knowledge‐based and statistically‐based techniques for reference retrieval Available to Purchase

This paper reports on a comparative evaluation of two computerised reference retrieval systems, INSTRUCT and PLEXUS. Instruct is a statistically‐based system based on best match searching and automatic index term weighting while Plexus uses expert systems techniques to improve access to a conventional Boolean search system. After an introduction to the retrieval techniques used by the two systems, their retrieval effectiveness is compared using a set of nineteen queries and 512 documents on the subject of gardening. The best results were obtained by using the terms suggested by the Plexus system as the basis for an Instruct search.