Empirical significance of document partitions is investigated as a function of index term-weight and similarity thresholds. Results show the same empirically preferred partitions can be detected by two independent strategies: an analysis of cluster-based retrieval analysis and an analysis of regularities in the underlying structure of the document…

Online seaches of sample topics in the area of forensic medicine were conducted in the following life science databases: Biosis Previews, Excerpta Medica, Medline, Scisearch, and Chemical Abstracts Search. Search outputs analyzed according to criteria of recall, uniqueness, overlap, and utility reveal the need for a cross-database approach to…

Discusses access to nontextual documents in large multimedia document bases. A hybrid information retrieval model, using queries in a hypertext environment for location of browsing areas, is presented; and two experiments using cluster-based descriptions of content are reported. (23 references) (EA)

Reports algorithm for calculation of term discrimination values that is sufficiently fast in operation to permit use of exact values. Evidence is presented to show that relationship between term discrimination and term frequency is crucially dependent upon type of inter-document similarity measure used for calculation of discrimination values. (13…

Zipfian laws for frequency distributions of word pairs and longer phrases are derived from text sample analysis. From crossing of Zipfian curves, it is deduced that number of multi-word phrases that occur frequently in text is surprisingly small, of same order of magnitude as number of individual word-types. (8 references) (EJS)

Describes a study that investigated subject retrieval in a group of humanities databases. Scatter by subject field and type of search term is discussed, the effectiveness of natural language and of controlled vocabulary are compared, and implications for system designers concerned with end-user searches in the humanities are suggested. (37…