Ryen W. White Ian Ruthven Joemon M. Jose C. J. van Rijsbergen Evaluating implicit feedback models using searcher simulations. 325-361 2005 23 ACM Trans. Inf. Syst. 3 http://doi.acm.org/10.1145/1080343.1080347 db/journals/tois/tois23.html#WhiteRJR05