Mathematical, Logical and Formal Methods in Information Retrieval: An Introduction to the Specia Issue

2 Abstract. Research on the use of mathematical, logical, and formal methods, has been central to Information Retrieval research for long time. Research in this area is important not only because it helps enhancing retrieval effectiveness, but also because it helps clarifying the underlying concepts of Information Retrieval. In this article we outline some of the major aspects of the subject, and summarise the papers of this special issue with respect to how they relate to these aspects. We conclude highlighting some directions of future research, which are needed in order to better understand the formal characteristics of Information Retrieval.