Estimating the recall performance of Web search engines Available to Purchase

This paper reports a comparison of the retrieval effectiveness of the Alta Vista, Excite and Lycos Web search engines. A method is described for comparing the recall of the three sets of searches, despite the fact that they are carried out on non‐identical sets of Web pages. It is thus possible, unlike previous comparative studies of Web search engines, to consider both recall and precision when evaluating the effectiveness of search engines.