Semantic Search as Inference: Applications in Health Informatics

In this thesis, we present models for semantic search: Information Retrieval (IR) models that elicit the meaning behind the words found in documents and queries rather than simply matching keywords. This is achieved by the integration of structured domain knowledge and data-driven information retrieval methods. The research is set within health informatics to tackle the unique challenges within this domain; specifically, how to bridge the 'semantic gap’; that is, how to overcome the mismatch between raw medical data and the way human beings interpret it. Bridging the semantic gap involves addressing two issues: semantics; that is, aligning the meaning or concepts behind words found in documents and queries; and leveraging inference, which utilises semantics to infer relevant information.

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