University of Amsterdam at the TREC 2007 Legal Track

In this paper, we document our official submissions to the TREC 2007 Legal track. Our main aims were two-fold: First, we experimented with using different query formulations trying to exploit the verbose topic statements. Second, we analysed how ranked retrieval methods can be fruitfully combined with traditional Boolean queries. Our main findings can be summarized as follows. First, we got mixed results trying to combine the original search request with terms extracted from the verbose topic statement. Second, by combining Boolean and ranked retrieval allows us to get the high recall of the Boolean retrieval, whilst precision scores show an improvement over both the Boolean and the ranked retrieval runs.