Explicit Web Search Result Diversification

Queries submitted to a web search engine are typically short and often ambiguous. With the enormous size of the Web, a misunderstanding of the information need underlying an ambiguous query can misguide the search engine, ultimately leading the user to abandon the origi-nally submitted query. In order to overcome this problem, a sensible approach is to diversify the documents retrieved for the user’s query. As a result, the likelihood that at least one of these documents will satisfy the user’s actual information need is increased. In this thesis, we argue that an ambiguous query should be seen as representing not one, but multiple information needs. Based upon this premise, we propose xQuAD—ExplicitQuery AspectDiversification, a novel probabilistic framework for search result diversification. In particular, the xQuAD framework naturally models several dimen-sions of the search result diversification problem in a principled ye