The motivation for our work is the observation that Web pages on a particular topic are often linked to other pages on the same topic. We model and analyze the problem of how to improve the classification of Web pages (that is, determining the topic of the page) by using link information. In our setting, an initial classifier examines the text of a Web page and assigns to it some classification, possibly mistaken. We investigate how to reduce the error probability using the observation above, thus building an improved classifier. We present a theoretical framework for this problem based on a random graph model and suggest two linear time algorithms, based on similar methods that have been proven effective in the setting of error-correcting codes. We provide simulation results to verify our analysis and to compare the performance of our suggested algorithms.

To appear in SODA 2000.