RGU-ISTI-Essex at TREC 2011 Session Track

Mining query recommendation from query logs has attracted a lot of attention in recent years. We propose to use query recommendations extracted from the logs of a web search engine to solve the session track tasks. The runs are obtained by using the Search Shortcuts recommender system. The Search Shortcuts technique uses an inverted index and the concept of “successful sessions” present in a web search engine’s query log to produce effective recommendations for both frequent and rare/unseen queries. We adapt the above technique as a query expansion tool and use it to expand the given queries for Session Track at TREC 2011. The expansion is generated by using a method which aims to consider all past queries in the session. The expansion terms obtained are then used to build a global, uniformly weighted, representation of the user session (RL2). Furthermore, the expansion terms are then combined with a ranked list of results in order to boost terms appearing more frequently in the final results lists (RL3). Finally, we also integrate dwell times and the weighting method obtained taking both result lists and clicks into account for assigning weights to the terms to expand the final query of the session. In addition to that, we submitted a baseline run. It is based on the observation that using the term “wikipedia” to expand the query resulted in a better retrieval performance for the tasks at last year’s session track at TREC 2010.