A large and growing number of web pages display contextual advertising based on keywords automatically extracted from the text of the page, and this is a substantial source of revenue supporting the web today. Despite the importance of this area, little formal, published research exists. We describe a system that learns how to extract keywords from web pages for advertisement targeting. The system uses a number of features, such as term frequency of each potential keyword, inverse document frequency, presence in meta-data, and how often the term occurs in search query logs. The system is trained with a set of example pages that have been hand-labeled with "relevant" keywords. Based on this training, it can then extract new keywords from previously unseen pages. Accuracy is substantially better than several baseline systems. Categories and Subject Descriptors ontent Analysis and Indexing]: Abstracting methods; H.4.m [Information Systems]: Miscellaneous General Terms Algorithm...
Wen-tau Yih, Joshua Goodman, Vitor R. Carvalho