Heuristic methods for the construction of term classes are presented and experimental results are obtained to illustrate the usefulness of the method. (Author/PF)

Discussion of models for information retrieval focuses on an application of linear algebra to text clustering, namely, a metric for measuring cluster quality based on the theory that cluster quality is proportional to the number of terms that are disjoint across the clusters. Explains term-document matrices and clustering algorithms. (Author/LRW)

Presents principles for determining profile of a system user based on analysis of co-occurrence of index terms in queries and pertinent documents. A procedure for determining index term weights, the information value of which depends on the degree of homogeneity of system users, is introduced. Three references are cited. (EJS)

Presents methods of information query building in selective dissemination of information systems based on user's publications and examines possible compatibility between user's information queries and his publications. Methods of information query construction determined by logical operators AND, OR, NOT and set of weighted keywords are described.…