ior. 7(1), 65-72. Eastman, C. and Jansen, B.J. (2003) Coverage, relevance, and ranking: the impact of query operators on Web search engine results, ACM Transactions on Information Systems. 21(4), 383-411. Spink, A., Jansen, B.J., Wolfram, D., and Saracevic, T. (2002) From e-sex to e-commerce: Web search changes, IEEE Computer. 35(3)