Information calculus for information retrieval

Information is and always has been an elusive concept; nevertheless many philosophers, mathematicians, logicians and computer scientists have felt that it is fundamental. Many attempts have been made to come up with some sensible and intuitively acceptable definition of information; up to now, none of these have succeeded. This work is based on the approach followed by Dretske, Barwise, and Devlin, who claimed that the notion of information starts from the position that given an ontology of objects individuated by a cognitive agent, it makes sense to speak of the information an object (e.g., a text, an image, a video) contains about another object (e.g., the query). This phenomenon is captured by the flow of information between objects. Its exploitation is the task of an Information Retrieval system. These authors proposed a theory of information that provides an analysis of the concept of information (any type, from any media) and the manner in which intelligent organisms (referred to as cognitive agents) handle and respond to the information picked up from their environment. They defined the nature of information flow and the mechanisms that give rise to such a flow. The theory, which is based on Situation Theory, is expressed with a calculus defined on channels. The calculus was defined so that it satisfies properties that are attributed to information and its flows. This paper demonstrates the connection between this calculus and Information Retrieval, and proposes a model of an Information Retrieval system based on this calculus. © 1996 John Wiley & Sons, Inc.