Search (11 results, page 1 of 1)

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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.

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Abstract

F.W. Lancaster's work has been immensely influential in library and information science. He has written on indexing and information system evaluation, and has been looked to as a pioneer in many areas. Here he describes precision and recall, the two most fundamental and widespread measures of information retrieval effectiveness.

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Source

Information retrieval experiment. Ed.: K. Sparck Jones

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Footnote

Wiederabgedruckt in: Readings in information retrieval. Ed.: K. Sparck Jones u. P. Willett. San Francisco: Morgan Kaufmann 1997. S.223-246.

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Abstract

Reports results of an evaluation of 2 expert systems designed for use in library reference services: ReferenceExpert (RE), developed by Houston University; and SourceFinder (SF), developed by Illinois University at Urbana-Champaign. The test group consisted of 60 graduate students at the initial stage of an intermediate level reference course. The evaluation involved test questions already used in an earlier study (College and research libraries 52(1991) no.5, S.454-465). Results indicated that: there was no significant difference between RE and SF students in the confidence they expressed regarding understanding of their test questions; no significant correlation was found between confidence in understanding the question and success in selecting appropriate sources; only 1/5 of the students agreed that the system they used could be considered 'intelligent'; the majority did not consider the system they used to be 'competent'; almost half agreed that the subject categories provided by the menus were too broad; a little more than half wer not satisfied with the information sources selected by their system; significantly more RE users than SF users agreed that they found the menu interface useful; and a keyword search capability was the feature most often mentioned as a needed system enhancement. Overall results indicated that current expert systems for the selection of reference sources cannot perform as well as experienced subject oriented reference librarians

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Abstract

An overview of levels and approaches in the evalution of knowledge-based systems is presented. There is a need for empirical studies using objective criteria in advance of completing the technical evaluation of such systems. A methodology for this type of evaluation developed for a particular knowledge-based indexing system is presented. It is suggested that the proposed study may serve as a model for the design of any evaluation in which the results of existing intellectual procedures are compared with results achieved when these procedures are aided by use of an appropriate expert system

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Abstract

Based partly on chapters in a forthcoming book 'Technology and Management in Library and Information Sciences' by F.W. Lancaster and B. Sandore. Some inportant functions of a research library operating largely in a networked digital environment are illustrated. The ability of artificial intelligence and expert system technologies to contribute to these functions is discussed, in the light of a report from the American Association for Artificial Intelligence, as well as experiences with these technologies in the library world and elsewhere

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Abstract

This piece of research traces the evolution of guidelines and principles for the construction of information retrieval thesauri from 1959 to 1993. We conclude that the majority of the basic problems of thesaurus construction has already been identified and solved by 1967 and that Eugene Wall, more than any other individual, has profoundly influenced the entire development in this area

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Abstract

Computer have been used in 2 areas of printed index production: to sort entries and fromat printed indexes, and to derive a series of index entries from a minimum intellectual input. Computer indexing enables more indexing terms to be used as well as weighted terms, links and roles. Interest in automatic indexing peaked in the mid-1960s and has since declined. Interest in machine-aided indexing concentrates on using the computer for on-line display or for indexing by extraction. Computers have also made possible the implementation of retrieval systems without indexing-free text systems. Considers future prospects and needs