Analysis of Web search queries with very few or no results

Nowadays search engines have significant impacts on people’s life with the rapid growth of World Wide Web. There are billions of web pages that include a huge amount of information. Search engines are indispensable tools for finding information on the Web. Despite the continuous efforts to improve the web search quality, a non-negligible fraction of user queries end up with very few or even no matching results in leading commercial web search engines. In this thesis, we provide the first detailed characterization of such queries based on an analysis of a real-life query log. Our experimental setup allows us to characterize the queries with few/no results and compare the mechanisms employed by the three major search engines to handle them. Furthermore, we build machine learning models for the prediction of query suggestion patterns and no-answer queries.