Advances in Information Retrieval

The classic IR model assumes a human engaged in activity that generates an “information need”. This need is verbalized and then expressed as a query to search engine over a defined corpus. In the past decade, Web search engines have evolved from a first generation based on classic IR algorithms scaled to web size and thus supporting only informational queries, to a second generation supporting navigational queries using web specific information (primarily link analysis), to a third generation enabling transactional and other “semantic” queries based on a variety of technologies aimed to directly satisfy the unexpressed “user intent”, thus moving further and further away from the classic model.