Introduction to special issue on contextual information retrieval systems

Context affects all aspects of Information Retrieval. A searcher's context affects how they interact with a retrieval system, what type of response they expect from a system and how they make decisions about the information objects they retrieve. Information contexts are formed through the creation, use and linkage of these objects within an information resource and the context of use impacts on how we evaluate retrieval systems. Our understanding of user and information context also influences how we design and construct retrieval systems themselves (Crestani and Ruthven, 2005; Ingwersen and Jarvelin, 2005; Ruthven et al., 2006). The ability to respond to context could allow retrieval systems to learn and predict what information a searcher needs, decide how and when this information should be presented and distinguish between different search goals and searcher preferences. How the designers of search systems should respond to context is an important issue for the development of retrieval systems and the appropriate use of context raises many research questions. For example, what aspects of a searcher's context can we recognise, how should context be utilised within a retrieval system to improve search performance, how can we exploit shared contexts and contexts over time, and how should we evaluate contextual IR systems?