Describes a study that collected statistics on the occurrence of terms used in searching an online catalog and investigated the correlation of the selection of terms with their occurrence in indexing. The discussion of the results includes implications for indexing theories. (19 references) (CLB)

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…

Summarizes the findings of a recent study on the indexing practices used in the Library and Information Science Abstracts (LISA) database. Descriptors, or indexing terms, from the thesaurus are analyzed; searching implications are discussed; and the relationship between the classification code and the descriptors is examined. (Contains 21…

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…

Summarizes the experimental evidence that indicates that text indexing systems based on the assignment of appropriately weighted single terms produce retrieval results superior to those obtained with more elaborate text representations, and provides baseline single term indexing models with which more elaborate content analysis procedures can be…

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)

Examines how informetric characteristics of information retrieval (IR) system databases can be used to help system designers decide what type of file structures would provide the best performance. The development of appropriate models describing database contents is highlighted in this first part of a two-part study. (30 references) (LRW)

This second report on a two-part study on the application of informetrics to information retrieval (IR) system design used models of database contents in a factorial simulation study at the University of Western Ontario. The study explored whether different file structures were better suited for different informetric environments. (32 references)…