Results of study examining identification of important literature in quantum mechanics using gamma test of association on two literature sets indicates that use of citation analysis alone or historical analysis alone will not result in same set of literature being produced. List of historical sources and 19 references are appended. (EJS)

Presents new methods for compressing bit matrices in large information retrieval systems which exploit possible correlations between rows of words and columns of documents. Three encoding methods are tested and compared--Shannon-Fano, arithmetic, and Huffman--and an appendix discusses binomial coefficients. (20 references) (LRW)

Investigates document ranking methods in thesaurus-based Boolean information retrieval systems and proposes a new thesaurus-based ranking algorithm called the Extended Relevance algorithm. Performance comparisons are made between the Extended Relevance algorithm and previous thesaurus-based ranking algorithms. (Contains 20 references.) (LRW)

Discussion of the use of scientific information disseminated in primary subject literature focuses on a study that developed a methodology for hypothesis testing that measured document obsolescence by means of citation analysis and content obsolescence by expert opinions and then compared the results. Information validity and information utility…