This book introduces the problem of content-based query replacement. It motivates the term correlation modeled using MRFs and the sampling based technique to learn the search phrase definitions. These definitions are used as alternative queries to achieve higher accuracy in several retrieval tasks. Retrieving relevant documents while eliminating irrelevant documents for an user s query is a challenging task which involves a good understanding of the relation between the data and the query as well as developing algorithms that can efficiently measure the relevance of the data to the query. As...