Search (16 results, page 1 of 1)

Lancaster, F.W.: Vocabulary control for information retrieval (1986) 0.01

0.010585917 = product of:
  0.07939438 = sum of:
    0.06224675 = weight(_text_:software in 217) [ClassicSimilarity], result of:
      0.06224675 = score(doc=217,freq=4.0), product of:
        0.12552431 = queryWeight, product of:
          3.9671519 = idf(docFreq=2274, maxDocs=44218)
          0.031640913 = queryNorm
        0.49589399 = fieldWeight in 217, product of:
          2.0 = tf(freq=4.0), with freq of:
            4.0 = termFreq=4.0
          3.9671519 = idf(docFreq=2274, maxDocs=44218)
          0.0625 = fieldNorm(doc=217)
    0.017147627 = product of:
      0.034295253 = sum of:
        0.034295253 = weight(_text_:22 in 217) [ClassicSimilarity], result of:
          0.034295253 = score(doc=217,freq=2.0), product of:
            0.110801086 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.031640913 = queryNorm
            0.30952093 = fieldWeight in 217, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0625 = fieldNorm(doc=217)
      0.5 = coord(1/2)
  0.13333334 = coord(2/15)

Classification: ST 271 Informatik / Monographien / Software und -entwicklung / Datenbanken, Datenbanksysteme, Data base management, Informationssysteme / Einzelne Datenbanksprachen und Datenbanksysteme
Date: 22. 4.2007 10:07:51
RVK: ST 271 Informatik / Monographien / Software und -entwicklung / Datenbanken, Datenbanksysteme, Data base management, Informationssysteme / Einzelne Datenbanksprachen und Datenbanksysteme

Lancaster, F.W.: Evaluating the performance of a large computerized information system (1985) 0.01
```
0.0074198637 = product of:
  0.055648975 = sum of:
    0.006439812 = product of:
      0.012879624 = sum of:
        0.012879624 = weight(_text_:online in 3649) [ClassicSimilarity], result of:
          0.012879624 = score(doc=3649,freq=2.0), product of:
            0.096027054 = queryWeight, product of:
              3.0349014 = idf(docFreq=5778, maxDocs=44218)
              0.031640913 = queryNorm
            0.13412495 = fieldWeight in 3649, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.0349014 = idf(docFreq=5778, maxDocs=44218)
              0.03125 = fieldNorm(doc=3649)
      0.5 = coord(1/2)
    0.049209163 = weight(_text_:evaluation in 3649) [ClassicSimilarity], result of:
      0.049209163 = score(doc=3649,freq=8.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.37076265 = fieldWeight in 3649, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.03125 = fieldNorm(doc=3649)
  0.13333334 = coord(2/15)
```
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.

Lancaster, F.W.: Information retrieval systems : characteristics, testing and evaluation (1979) 0.01

0.006561222 = product of:
  0.098418325 = sum of:
    0.098418325 = weight(_text_:evaluation in 7270) [ClassicSimilarity], result of:
      0.098418325 = score(doc=7270,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.7415253 = fieldWeight in 7270, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.125 = fieldNorm(doc=7270)
  0.06666667 = coord(1/15)

Lancaster, F.W.; Gillespie, C.J.: Design and evaluation of information systems (1970) 0.01

0.006561222 = product of:
  0.098418325 = sum of:
    0.098418325 = weight(_text_:evaluation in 243) [ClassicSimilarity], result of:
      0.098418325 = score(doc=243,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.7415253 = fieldWeight in 243, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.125 = fieldNorm(doc=243)
  0.06666667 = coord(1/15)

Lancaster, F.W.: Evaluation of expert systems in information service applications (1994) 0.01

0.0057410696 = product of:
  0.08611604 = sum of:
    0.08611604 = weight(_text_:evaluation in 8905) [ClassicSimilarity], result of:
      0.08611604 = score(doc=8905,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.64883465 = fieldWeight in 8905, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.109375 = fieldNorm(doc=8905)
  0.06666667 = coord(1/15)

Lancaster, F.W.; Ulvila, J.W.; Humphrey, S.M.; Smith, L.C.; Allen, B.; Herner, S.: Evaluation of interactive knowledge-based systems : overview and design for empirical testing (1996) 0.01
```
0.0057410696 = product of:
  0.08611604 = sum of:
    0.08611604 = weight(_text_:evaluation in 3000) [ClassicSimilarity], result of:
      0.08611604 = score(doc=3000,freq=8.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.64883465 = fieldWeight in 3000, product of:
          2.828427 = tf(freq=8.0), with freq of:
            8.0 = termFreq=8.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.0546875 = fieldNorm(doc=3000)
  0.06666667 = coord(1/15)
```
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

Lancaster, F.W.: Evaluation within the environment of an operating information service (1981) 0.01

0.0057410696 = product of:
  0.08611604 = sum of:
    0.08611604 = weight(_text_:evaluation in 3150) [ClassicSimilarity], result of:
      0.08611604 = score(doc=3150,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.64883465 = fieldWeight in 3150, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.109375 = fieldNorm(doc=3150)
  0.06666667 = coord(1/15)

Lancaster, F.W.: Evaluation in the context of the digital library (1996) 0.01

0.0056821858 = product of:
  0.08523278 = sum of:
    0.08523278 = weight(_text_:evaluation in 7886) [ClassicSimilarity], result of:
      0.08523278 = score(doc=7886,freq=6.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.6421798 = fieldWeight in 7886, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.0625 = fieldNorm(doc=7886)
  0.06666667 = coord(1/15)

Abstract: Digital libraries are sufficiently differnt from more traditional print on paper libraries to present a new set of parameters relating to the evaluation of its use. Discusses evaluation criteria, problems and methods relevant to the digital library environment

Lancaster, F.W.: MEDLARS : report on the evaluation of its operating effiency (1961) 0.00

0.004920917 = product of:
  0.07381375 = sum of:
    0.07381375 = weight(_text_:evaluation in 1931) [ClassicSimilarity], result of:
      0.07381375 = score(doc=1931,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.556144 = fieldWeight in 1931, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.09375 = fieldNorm(doc=1931)
  0.06666667 = coord(1/15)

Lancaster, F.W.; Warner, A.J.: Information retrieval today (1993) 0.00

0.0041007637 = product of:
  0.061511453 = sum of:
    0.061511453 = weight(_text_:evaluation in 4607) [ClassicSimilarity], result of:
      0.061511453 = score(doc=4607,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.4634533 = fieldWeight in 4607, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.078125 = fieldNorm(doc=4607)
  0.06666667 = coord(1/15)

Content: Es handelt sich um die 3. Aufl. von: 'Information retrieval systems: characteristics, testing and evaluation' des ersten Autors

Su, S.-F.; Lancaster, F.W.: Evaluation of expert systems in reference service applications (1995) 0.00
```
0.0035513658 = product of:
  0.053270485 = sum of:
    0.053270485 = weight(_text_:evaluation in 4014) [ClassicSimilarity], result of:
      0.053270485 = score(doc=4014,freq=6.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.40136236 = fieldWeight in 4014, product of:
          2.4494898 = tf(freq=6.0), with freq of:
            6.0 = termFreq=6.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.0390625 = fieldNorm(doc=4014)
  0.06666667 = coord(1/15)
```
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

Lancaster, F.W.: Precision and recall (2009) 0.00

0.003280611 = product of:
  0.049209163 = sum of:
    0.049209163 = weight(_text_:evaluation in 3866) [ClassicSimilarity], result of:
      0.049209163 = score(doc=3866,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.37076265 = fieldWeight in 3866, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.0625 = fieldNorm(doc=3866)
  0.06666667 = coord(1/15)

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.

Lancaster, F.W.: Indexing and abstracting in theory and practice (1998) 0.00
```
0.0024604585 = product of:
  0.036906876 = sum of:
    0.036906876 = weight(_text_:evaluation in 4141) [ClassicSimilarity], result of:
      0.036906876 = score(doc=4141,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.278072 = fieldWeight in 4141, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.046875 = fieldNorm(doc=4141)
  0.06666667 = coord(1/15)
```
Content

Enthält die Kapitel: Indexing principles, Indexing practice, Precoordinate indexes, Consistency of indexing, Quality of indexing, Abstracts: types and functions, Writing the Abstract, Evaluation aspects, Approaches used in indexing and abstracting services, Enhancing the indexing, On the indexing and abstracting of imaginative works, Indexing multimedia sources, Texte searching, Automatic indexing, automatic abstracting, and related procedures, Indexing and the Internet, The future of indexing and abstracting, exercises in indexing and abstracting

Lancaster, F.W.: Indexing and abstracting in theory and practice (2003) 0.00

0.0024604585 = product of:
  0.036906876 = sum of:
    0.036906876 = weight(_text_:evaluation in 4913) [ClassicSimilarity], result of:
      0.036906876 = score(doc=4913,freq=2.0), product of:
        0.13272417 = queryWeight, product of:
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.031640913 = queryNorm
        0.278072 = fieldWeight in 4913, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.1947007 = idf(docFreq=1811, maxDocs=44218)
          0.046875 = fieldNorm(doc=4913)
  0.06666667 = coord(1/15)

Content: Covers: indexing principles and practice; precoordinate indexes; consistency and quality of indexing; types and functions of abstracts; writing an abstract; evaluation theory and practice; approaches used in indexing and abstracting services; indexing enhancement; natural language in information retrieval; indexing and abstracting of imaginative works; databases of images and sound; automatic indexing and abstracting; the future of indexing and abstracting services

Xu, H.; Lancaster, F.W.: Redundancy and uniqueness of subject access points in online catalogs (1998) 0.00
```
9.10727E-4 = product of:
  0.013660905 = sum of:
    0.013660905 = product of:
      0.02732181 = sum of:
        0.02732181 = weight(_text_:online in 1788) [ClassicSimilarity], result of:
          0.02732181 = score(doc=1788,freq=4.0), product of:
            0.096027054 = queryWeight, product of:
              3.0349014 = idf(docFreq=5778, maxDocs=44218)
              0.031640913 = queryNorm
            0.284522 = fieldWeight in 1788, product of:
              2.0 = tf(freq=4.0), with freq of:
                4.0 = termFreq=4.0
              3.0349014 = idf(docFreq=5778, maxDocs=44218)
              0.046875 = fieldNorm(doc=1788)
      0.5 = coord(1/2)
  0.06666667 = coord(1/15)
```
Abstract

Reports results of an analysis of 205 randomly selected records from the OCLC OLUC, to test the assumption that online catalogues have greatly improved subject searching capabilities, over card catalogues, by making other fields in the records searchable as subject access points (SAPs). Results showed considerable overlap (duplication) among the SAPs provided by the title, subject heading and classification number fields. On average, little more than 4 unique, unduplicated access points were found per record. Where title and classification number fields do add some access points not provided by subject headings, the increase is less than many librarians might be expected. Suggests that OPACs might outperform catalogues more in precision than in recall by allowing greater discrimination in searching; terms from different fields may be combined; titles offer greater specifity; searches can be limited by date, language or other criteria
Lancaster, F.W.; Connell, T.H.; Bishop, N.; McCowan, S.: Identifying barriers to effective subject access in library catalogs (1991) 0.00
```
7.513114E-4 = product of:
  0.011269671 = sum of:
    0.011269671 = product of:
      0.022539342 = sum of:
        0.022539342 = weight(_text_:online in 2259) [ClassicSimilarity], result of:
          0.022539342 = score(doc=2259,freq=2.0), product of:
            0.096027054 = queryWeight, product of:
              3.0349014 = idf(docFreq=5778, maxDocs=44218)
              0.031640913 = queryNorm
            0.23471867 = fieldWeight in 2259, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.0349014 = idf(docFreq=5778, maxDocs=44218)
              0.0546875 = fieldNorm(doc=2259)
      0.5 = coord(1/2)
  0.06666667 = coord(1/15)
```
Abstract

51 subject searches were performed in an online catalog containing about 4,5 million records. Their success was judges in terms of lists of items, known to be relevant to the various topics, compiled by subject specialists (faculty members or authors of articles in specialized encyclopedias). Many of the items known to be relevant were not retrieved, even in very broad searches that sometimes retrieved several hundred records, and very little could be done to make them retrievable within the constraints of present cataloging practice. Librarians should recognize that library catalogs, as now implemented, offer only the most primitive of subject access and should seek to develop different types of subject access tools. - Vgl auch Letter (B.H. Weinberg) in: LTRS 36(1992) S.123-124.

Search (16 results, page 1 of 1)

Authors

Years

Types

Themes

Subjects

Classifications