搜索引擎經典書籍 This book provides an overview of the important issues in information retrieval, and how those issues affect the design and implementation of search engines. Not every topic is covered at the same level of detail. We focus instead on what we consider to be the most important alternatives to implementing search engine components and the information retrieval models underlying them. Web search engines are obviously a major topic, and we base our coverage primarily on the technology we all use on the Web,1 but search engines are also used in many other applications. That is the reason for the strong emphasis on the information retrieval theories and concepts that underlie all search engines.