The calculation of web impact factors

This case study reports the investigations into the feasibility and reliability of calculating impact factors for web sites, called Web Impact Factors (Web‐IF). The study analyses a selection of seven small and medium scale national and four large web domains as well as six institutional web sites over a series of snapshots taken of the web during a month. The data isolation and calculation methods are described and the tests discussed. The results thus far demonstrate that Web‐IFs are calculable with high confidence for national and sector domains whilst institutional Web‐IFs should be approached with caution. The data isolation method makes use of sets of inverted but logically identical Boolean set operations and their mean values in order to generate the impact factors associated with internal‐ (self‐) link web pages and external‐link web pages. Their logical sum is assumed to constitute the workable frequency of web pages linking up to the web location in question. The logical operations are necessary to overcome the variations in retrieval outcome produced by the AltaVista search engine.