Discusses the basic elements of a global cognitive theory for information retrieval (IR) interaction from a cognitive point of view. Within this framework are outlined the principles underlying the concept of polyrepresentation applied simultaneously to the user's cognitive space and the information space of IR systems. Contains 95 references.…

This comment attempts to identify different "semiotic perspectives" proposed by the authors of this special issue according to the problems they discuss. These problems can be distinguished as problems concerning the representation of mathematical knowledge, the definition and objectivity of meaning, epistemological questions of learning and…

Introduces a framework for comparing and evaluating knowledge representation schemes based on the requirements for "good" representation discussed in extant literature. Comparative analysis and evaluation of four popular knowledge representation schemes--Logic, Production Rules, Semantic Nets and Frames--are discussed in support of validity and…