The study measured whether two search engines retrieve different Web documents for 6 queries. Two different search engines, Alta Vista in terms of keyword search engines and Yahoo in terms of subject directory engines were measured using as criteria, total number of documents retrieved, total number of relevant documents retrieved, recall and precision ratios. In addition, Alta Vista was suitable for specific and technical terms, while Yahoo was effective for general and plain terms. However, more elaborate research needs to be tested in terms of query characteristics.