Explores inter-record linkage relationships of a bibliographic hypertext system through the use of descriptor term co-occurrences. Using term distribution and term exhaustivity data for an existing system, three models of term co-occurrence are developed and tested against the observed data. (Author/LRW)

Discussion of a new method of index term dictionary compression in an inverted-file-oriented database highlights a technique of word coding, which generates short fixed-length codes obtained from the index terms themselves by analysis of monogram and bigram statistical distributions. Substantial savings in communication channel utilization are…

This update of 1978 bibliometric study of online retrieval literature reveals that: literature has continued to grow, reaching peak annual output (504 papers) in 1981; conference literature has become centralized in four major proceedings; online retrieval papers have appeared in 479 journals; and 31 authors have contributed 10 or more papers.…

Derives the underlying structure of the Zipf distribution, with emphasis on its application to word frequencies in the inverted files of automatic bibliographic systems, and applies the Zipfian model to the National Library of Medicine's MEDLINE database. An appendix on the Zipfian mean and 12 references are included. (Author/JL)

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…

Discusses a study conducted at Ohio State University Libraries to develop and test a model that accurately estimates number of terminals required in an online public access catalog system. Data collection, research methodology, standard statistical distributions, and queuing models are noted. Four references are cited. (EJS)

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)

Discussion of online bibliographic database searches focuses on a software system, SORT-AID/SABRE, that ranks retrieved citations in terms of relevance. Results of a comprehensive user evaluation of the relevance ranking procedure to determine its effectiveness are presented, and implications for future work are suggested. (10 references) (LRW)