Diese Datenbank enthält über 40.000 Dokumente zu Themen aus den Bereichen Formalerschließung – Inhaltserschließung – Information Retrieval.
© 2015 W. Gödert, TH Köln, Institut für Informationswissenschaft / Powered by litecat, BIS Oldenburg (Stand: 04. Juni 2021)
81Renford, B.: Searching MELVYL MEDLINE.
In: DLA bulletin. 8(1988) no.3, S.3-8.
Abstract: With the addition of the current MEDLINE data base and the MELVYL MEDLINE interface, the MELVYL on-line catalogue now provides access to MEDLINE for users of the California University cmpuses. The basics of searching MELVYL MEDLINE are described.
Objekt: MEDLINE ; MELVYL
82Sievert, M.E. ; McKinin, E.J. ; Slough, M.: ¬A comparison of indexing and full-text for the retrieval of clinical medical literature.
In: ASIS'88. Information technology: planning for the next fifty years. Proceedings of the 51st annual meeting of the American Society for Information Science, Atlanta, Georgia, 23-27.10.1988. Vol.25. Ed. by C.L. Borgman and E.Y.H. Pai. Medford, New Jersey : Learned Information, 1988. S.143-146.
Abstract: The availability of two full text data bases in the clinical medical journal literature, MEDIS from Mead Data Central and CCML from BRS Information Technologies, provided an opportunity to compare the efficacy of the full text to the traditional, indexed system, MEDLINE for retrieval effectiveness. 100 searches were solicited from an academic health sciences library and the request were searched on all 3 data bases. The results were compared and preliminary analysis suggests that the full text data bases retrieve a greater number of relevant citations and MEDLINE achieves higher precision.
Objekt: MEDLINE ; MEDIS ; CCML
83MacCain, K.W. ; White, H.D. ; Griffith, B.C.: Comparing retrieval performance in online data bases.
In: Information processing and management. 23(1987), S.539-553.
Abstract: This study systematically compares retrievals on 11 topics across five well-known data bases, with MEDLINE's subject indexing as a focus. Each topic was posed by a researcher in the medical behavioral sciences. Each was searches in MEDLINE, EXCERPTA MEDICA, and PSYCHINFO, 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 capabiblity 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 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
85Lancaster, F.W.: Evaluating the performance of a large computerized information system.
In: Theory of subject analysis: a sourcebook. Ed.: L.M. Chan, et al. Littleton, CO : Libraries Unlimited, 1985. S.326-339.
Abstract: F. W. Lancaster is known for his writing an the state of the art in librarylinformation science. His skill in identifying significant contributions and synthesizing literature in fields as diverse as online systems, vocabulary control, measurement and evaluation, and the paperless society have earned him esteem as a chronicler of information science. Equally deserving of repute is his own contribution to research in the discipline-his evaluation of the MEDLARS operating system. The MEDLARS study is notable for several reasons. It was the first large-scale application of retrieval experiment methodology to the evaluation of an actual operating system. As such, problems had to be faced that do not arise in laboratory-like conditions. One example is the problem of recall: how to determine, for a very large and dynamic database, the number of documents relevant to a given search request. By solving this problem and others attendant upon transferring an experimental methodology to the real world, Lancaster created a constructive procedure that could be used to improve the design and functioning of retrieval systems. The MEDLARS study is notable also for its contribution to our understanding of what constitutes a good index language and good indexing. The ideal retrieval system would be one that retrieves all and only relevant documents. The failures that occur in real operating systems, when a relevant document is not retrieved (a recall failure) or an irrelevant document is retrieved (a precision failure), can be analysed to assess the impact of various factors an the performance of the system. This is exactly what Lancaster did. He found both the MEDLARS indexing and the McSH index language to be significant factors affecting retrieval performance. The indexing, primarily because it was insufficiently exhaustive, explained a large number of recall failures. The index language, largely because of its insufficient specificity, accounted for a large number of precision failures. The purpose of identifying factors responsible for a system's failures is ultimately to improve the system. Unlike many user studies, the MEDLARS evaluation yielded recommendations that were eventually implemented.* Indexing exhaustivity was increased and the McSH index language was enriched with more specific terms and a larger entry vocabulary.
Anmerkung: Nachdruck des Originalartikels mit Kommentierung durch die Herausgeber ; Original in: Journal of the American Medical Association 207(1969) S.114-120.
87Lancaster, F.W.: MEDLARS : report on the evaluation of its operating effiency.
In: American documentation. 20(1969), S.119-142.
Anmerkung: Wiederabgedruckt in: Readings in information retrieval. Ed.: K. Sparck Jones u. P. Willett. San Francisco: Morgan Kaufmann 1997. S.223-246.