Institute of Software, Chinese Academy of Sciences (ISCAS) participated in TREC-2004, submitting 18 runs. We focus on studying the problem of the combination of the user- and query-information from clarification forms and metadata. We provided two kinds of Clarification Form. Our experiment shows the CF2 is more effective than CF1. We use Google as a resource for query expansion base on metadata subject and familiarity together, and the R-prec is increased from 0.2308 (baseline) to 0.2646 (+14.6%). Our approach to exploiting the metadata Genre and Geography yield negative result when used alone, however, surprisedly, when combinate metadata Genre and metadata Geography with CF2 respectively, we get an increase (+1.2%) and (+5.4%) than use CF2 alone. Our combination of CF2 and metadata relt_text is the best results of all the TREC runs (R-prec), and in this run, the R-prec is increased from 0.3303 (CF2 alone) to 0.3766 (+14%), and from 0.2888 (metadata rel-text alone) to 0.3766 (+30.4%). From the results we can see the information from user (CF2) and the information from query (metadata relt-text) may complement each other.
['Le Sun', 'Junlin Zhang', 'Yufang Sun']
ISCAS at TREC-2004: HARD Track