Belver C. Griffith

Author cocitation: A literature measure of intellectual structure

It is shown that the mapping of a particular area of science, in this case information science, can be done using authors as units of analysis and the cocitations of pairs of authors as the variable that indicates their “distances” from each other. The analysis assumes that the more two authors are cited together, the closer the relationship between them. The raw data are cocitation counts drawn online from Social Scisearch (Social Sciences Citation Index) over the period 1972–1979. The resulting map shows (1) identifiable author groups (akin to “schools”) of information science, (2) locations of these groups with respect to each other, (3) the degree of centrality and peripherality of authors within groups, (4) proximities of authors within group and across group boundaries (“border authors” who seem to connect various areas of research), and (5) positions of authors with respect to the maps axes, which were arbitrarily set spanning the most divergent groups in order to aid interpretation. Cocitation analysis of authors offers a new technique that might contribute to the understanding of intellectual structure in the sciences and possibly in other areas to the extent that those areas rely on serial publications. The technique establishes authors, as well as documents, as an effective unit in analyzing subject specialties.

Communication and information processing within scientific disciplines: Empirical findings for Psychology

Abstract Scientific disciplines can be regarded as social devices which have, as one function, the analysis and reduction of raw information to assimilated knowledge of a type which can be transmitted through professional training. Data on information flow in psychology reveal a lengthy series of disseminatins to various audiences. The earliest disseminations involve feedback to scientific workers and result in refinements of the product of research; later disseminations are interwoven with processes of evaluation and selection and are directed toward the creation of an integrated and tested body of knowledge. The reported data furnish an empirical base for Zimans consensual model of science and illuminate difficulties which have arisen in the design and implementation of information systems.

Quality of indexing in online data bases

Abstract We describe practical tests by which the quality of subject indexing in online bibliographic data bases can be compared and judged. The tests are illustrated with 18 clusters of documents from the medical behavioral science literature and with terms drawn from MEDLINE, PsycINFO, BIOSIS, and Excerpta Medica. Each test involves obtaining a cluster of about five documents known on some grounds to be related in subject matter, and retrieving their descriptors from at least two data bases. We then tabulate the average number of descriptors applied to the documents, the number of descriptors applied to all and to a majority of the documents in the cluster, and the relative rarity of the applied descriptors. Comparable statistics emerge on how each data base links related documents and discriminates broadly and finely among documents. We also gain qualitative insights into the expressiveness and pertinence of the available indexing terms.

Comparing retrieval performance in online data bases

Abstract This study systematically compares retrievals on 11 topics across five well-known data bases, with MEDLINEs subject indexing as a focus. Each topic was posed by a researcher in the medical behavioral sciences. Each was searched in MEDLINE, EXCERPTA MEDICA, and PSYCINFO, which permit descriptor searches, and in SCISEARCH and SOCIAL SCISEARCH, which express topics through cited references. Searches on each topic were made with (1) descriptors, (2) cited references, and (3) natural language (a capability common to all five data bases). The researchers who posed the topics judged the results. In every case, the set of records judged relevant was used to calculate recall, precision, and novelty ratios. Overall, MEDLINE had the highest recall percentage (37%), followed by SSCI (31%). All searches resulted in high precision ratios; novelty ratios of data bases and searches varied widely. Differences in record format among data bases affected the success of the natural language retrievals. Some 445 documents judged relevant were not retrieved from MEDLINE using its descriptors; they were found in MEDLINE through natural language or in an alternative data base. An analysis was performed to examine possible faults in MEDLINE subject indexing as the reason for their nonretrieval. However, no patterns of indexing failure could be seen in those documents subsequently found in MEDLINE through known-item searches. Documents not found in MEDLINE primarily represent failures of coverage—articles were from nonindexed or selectively indexed journals. Recommendations to MEDLINE managers include expansion of record format and modification of journal and article selection policies.

An Empirical Examination of Bradford's Law and the Scattering of Scientific Literature.

Twenty‐three data sets representing the documents retrieved by a wide variety of searches were examined for correspondence to Bradfords Law. Regression lines fit to the data sets showed all correlations in excess of 0.96. Thus, the fitted line, as customarily specified by slope and intercept, can serve as a good representation of an entire data set. Slope can be shown to be almost entirely determined by the total number of articles retrieved. Over two‐thirds of the variance in the intercept is accounted for by the total number of journal titles retrieved. These findings weigh against earlier speculation that slope and intercept depended on such characteristics as breadth of subject area, topic, time period, or search technique. The findings show that Bradfords Law is the reflection of some underlying process not related to the characteristics of the search mechanism or the nature of the literature. The authors conclude that there is instead a basic probabilistic mechanism underlying the law.

A method for partitioning the journal literature

Citation databases can be readily partitioned by examining the extent to which journals “feed back” to one another. A method has been developed to divide large files into clusters of journals without requiring the use of arbitrary starting points. Results are discussed relative to biomedical literature, and these findings are shown to be subsumed under a more general hypothesis regarding the structure of scientific literature.

Informal contacts in science: a probabilistic model for communication processes.

Significant contacts among scientists within research specialties are generally infrequent and are distributed as an essentially random process, the pattern of most contacts conforming to a Poisson distribution. Extremely productive persons in a specialty, however, seem to form a separate distribution; they have a considerably higher number of contacts.

Test of methods for evaluating bibliographic databases: an analysis of the National Library of Medicine's handling of literatures in the medical behavioral sciences

This article reports on five separate studies designed for the National Library of Medicine (NLM) to develop and test methodologies for evaluating the products of large databases. The methodologies were tested on literatures of the medical behavioral sciences (MBS). One of these studies examined how well NLM covered MBS monographic literature using CATLINE and OCLC. Another examined MBS journal and serial literature coverage in MEDLINE and other MBS‐related databases available through DIALOG. These two studies used 1010 items derived from the reference lists of sixty‐one journals, and tested for gaps and overlaps in coverage in the various databases. A third study examined the quality of the indexing NLM provides to MBS literatures and developed a measure of indexing as a system component. The final two studies explored how well MEDLINE retrieved documents on topics submitted by MBS professionals and how online searchers viewed MEDLINE (and other systems and databases) in handling MBS topics. The five studies yielded both broad research outcomes and specific recommendations to NLM.

The National Scientific Meeting in Psychology as a Changing Social System

A presentation of the research of the American Psychological Associations Project in Scientific Information Exchange in Psychology. The techniques used are embodied in analyses of two APA meetings separated by thirty years. The meetings reflect the changes obtaining in psychology as a field of endeavor.

Exact fits to large ranked, bibliometric distributions

A system of software and analysis was tested and good fits were obtained to quite large distributions. Its use was found to be sufficiently swift to make repeated modelling feasible. There were results of possible interest regarding the rates of change between adjacent ranks and the identification and contribution of a “core” literature. This approach should facilitate future comparisons among models with large data sets.