A Survey of Ranking Theory

Abstract

With the huge number of web pages that exist today, search engines assume an important role in the current Internet. But even if they allow to find relevant pages for any search topic, nowadays the number of results returned is often too big to be carefully explored. Moreover, the needs of the users vary, so that what may be interesting for one may be completely irrelevant for another. The role of ranking algorithms is thus crucial: select the pages that are most likely be able to satisfy the user’s needs, and bring them in the top positions. In this survey I will cover the most popular algorithms used today by the search engines: PageRank, HITS and SALSA.