New versions of PageRank employing alternative Web document models

We introduce several new versions of PageRank (the link based Web page ranking algorithm), based upon an information science perspective on the concept of the Web document. Although the Web page is the typical indivisible unit of information in search engine results and most Web information retrieval algorithms, other research has suggested that aggregating pages based upon directories and domains gives promising alternatives, particularly when Web links are the object of study. The new algorithms introduced based upon these alternatives were used to rank four sets of Web pages. The ranking results were compared with human subjects’ rankings. The results of the tests were somewhat inconclusive: the new approach worked well for the set that includes pages from different Web sites; however, it does not work well in ranking pages that are from the same site. It seems that the new algorithms may be effective for some tasks but not for others, especially when only low numbers of links are involved or the pages to be ranked are from the same site or directory.