Abstract not found

Web search result clustering aims to facilitate information search on the Web. Rather than presenting the results of a query as a flat list, these are grouped on the basis of their similarity and subsequently shown to the user as a list of possibly labeled clusters. Each cluster is supposed to represent a different meaning of the input query, thus taking into account the language ambiguity, i.e. polysemy, issue. However, Web clustering methods typically rely on some shallow notion of textual similarity of search result snippets. As a result, text snippets with no word in common tend to be clustered separately, even if they share the same meaning, whereas snippets with words in common may be grouped together even if they refer to different meanings of the input query. In this paper, we present a novel approach to Web search result clustering based on the automatic discovery of word senses from raw text, a task referred to as Word Sense Induction (WSI). Key to our approach is to first acquire the senses (i.e., meanings) of an ambiguous query and then cluster the search results based on their semantic similarity to the word senses induced. Our experiments, conducted on datasets of ambiguous queries, show that our approach outperforms both Web clustering and search engines. 1.

Web search queries are often ambiguous or multi-faceted, which makes a simple ranked list of results inadequate. To assist information finding for such faceted queries, we explore a technique that explicitly represents interesting facets of a query using groups of semantically related terms extracted from search results. As an example, for the query “baggage allowance”, these groups might be different airlines, different flight types (domestic, international), or different travel classes (first, business, economy). We name these groups query facets and the terms in these groups facet terms. We develop a supervised approach based on a graphical model to recognize query facets from the noisy candidates found. The graphical model learns how likely a candidate term is to be a facet term as well as how likely two terms are to be grouped together in a query facet, and captures the dependencies between the two factors. We propose two algorithms for approximate inference on the graphical model since exact inference is intractable. Our evaluation combines recall and precision of the facet terms with the grouping quality. Experimental results on a sample of web queries show that the supervised method significantly outperforms existing approaches, which are mostly unsupervised, suggesting that query facet extraction can be effectively learned.

Faceted search helps users by offering drill-down options as a complement to the keyword input box, and it has been used successfully for many vertical applications, including e-commerce and digital libraries. However, this idea is not well explored for general web search, even though it holds great potential for assisting multi-faceted queries and exploratory search. In this paper, we explore this potential by extend-ing faceted search into the open-domain web setting, which we call Faceted Web Search. To tackle the heterogeneous nature of the web, we propose to use query-dependent au-tomatic facet generation, which generates facets for a query instead of the entire corpus. To incorporate user feedback on these query facets into document ranking, we investigate both Boolean filtering and soft ranking models. We evalu-ate Faceted Web Search systems by their utility in assist-ing users to clarify search intent and find subtopic informa-tion. We describe how to build reusable test collections for such tasks, and propose an evaluation method that considers both gain and cost for users. Our experiments testify to the potential of Faceted Web Search, and show Boolean filter-ing feedback models, which are widely used in conventional faceted search, are less effective than soft ranking models.

Entity queries constitute a large fraction of web search queries and most of these queries are in the form of an entity mention plus some context terms that represent an intent in the context of that entity. We refer to these entity-oriented search intents as entity aspects. Recognizing entity aspects in a query can improve various search applications such as providing direct answers, diversifying search results, and recommending queries. In this paper we focus on the tasks of identifying, ranking, and recommending entity aspects, and propose an approach that mines, clusters, and ranks such aspects from query logs. We perform large-scale experiments based on users ’ search ses-sions from actual query logs to evaluate the aspect ranking and recommendation tasks. In the aspect ranking task, we aim to sat-isfy most users ’ entity queries, and evaluate this task in a query-independent fashion. We find that entropy-based methods achieve the best performance compared to maximum likelihood and lan-guage modeling approaches. In the aspect recommendation task, we recommend other aspects related to the aspect currently being queried. We propose two approaches based on semantic relatedness and aspect transitions within user sessions and find that a combined approach gives the best performance. As an additional experiment, we utilize entity aspects for actual query recommendation and find that our approach improves the effectiveness of query recommen-dations built on top of the query-flow graph.