Semantics of query rewriting patterns in search logs

Examining past query reformulations of users in the logs of a search engine shows that not only query rewriting that precises the focus of a query but also queries expressing some topical shift from the original query can help users in their search activities. We examine three methods to explore query rewriting patterns, namely co-click based, co-topic based and co-session based methods. Each method has its own semantic characteristic: the co-click based and the co-topic based methods typically exploit specialization patterns with different granularity whereas the co-session based method is able to extract topic shift patterns. We show the different semantic relations of extracted query pairs by using large scale web annotations for Japanese web pages.