Natural Language Information Retrieval: TREC-7 Report

Adhoc topics were processed at GE using both automatic and manual topic expansion. We used the interactive Query Expansion Tool to expand topics with automatically generated summaries of top 30 documents retrieved by the original topic. Manual intervention was restricted to accept/reject decisions on summaries. We observed time limit of 10 minutes per topic. Automatic topics expansion was done by replacing human summary selection by an automatic procedure, which accepted only the summaries that obtained sufficiently high scores. Two sets of expanded topics (automatic and manual) were sent to Helsinki for NL processing, and then on to Rutgers for retrieval. Rankings were obtained from each stream index and then merged using a combined strategy developed at GE and SICS.