Search (5 results, page 1 of 1)

0.008028265 = product of:
  0.04816959 = sum of:
    0.04816959 = weight(_text_:wide in 7151) [ClassicSimilarity], result of:
      0.04816959 = score(doc=7151,freq=2.0), product of:
        0.19679762 = queryWeight, product of:
          4.4307585 = idf(docFreq=1430, maxDocs=44218)
          0.044416238 = queryNorm
        0.24476713 = fieldWeight in 7151, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          4.4307585 = idf(docFreq=1430, maxDocs=44218)
          0.0390625 = fieldNorm(doc=7151)
  0.16666667 = coord(1/6)

Abstract

This article revisits the debate concerning controlled and natural indexing languages, as used in searching the databases of the online hosts, in-house information retrieval systems, online public access catalogues and databases stored on CD-ROM. The debate was first formulated in the early days of information retrieval more than a century ago but, despite significant advance in technology, remains unresolved. The article divides the history of the debate into four eras. Era one was characterised by the introduction of controlled vocabulary. Era two focused on comparisons between different indexing languages in order to assess which was best. Era three saw a number of case studies of limited generalisability and a general recognition that the best search performance can be achieved by the parallel use of the two types of indexing languages. The emphasis in Era four has been on the development of end-user-based systems, including online public access catalogues and databases on CD-ROM. Recent developments in the use of expert systems techniques to support the representation of meaning may lead to systems which offer significant support to the user in end-user searching. In the meantime, however, information retrieval in practice involves a mixture of natural and controlled indexing languages used to search a wide variety of different kinds of databases

0.006871327 = product of:
  0.04122796 = sum of:
    0.04122796 = product of:
      0.08245592 = sum of:
        0.08245592 = weight(_text_:programs in 554) [ClassicSimilarity], result of:
          0.08245592 = score(doc=554,freq=2.0), product of:
            0.25748047 = queryWeight, product of:
              5.79699 = idf(docFreq=364, maxDocs=44218)
              0.044416238 = queryNorm
            0.32024145 = fieldWeight in 554, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              5.79699 = idf(docFreq=364, maxDocs=44218)
              0.0390625 = fieldNorm(doc=554)
      0.5 = coord(1/2)
  0.16666667 = coord(1/6)

Abstract

The development of regional on-line catalogs and in-house information systems for retrieval of references provide examples of the impact of indexing theory and applications on technical processing. More emphasis must be given to understanding the techniques for evaluating the effectiveness of a file, irrespective of whether that file was created as a library catalog or an index to information sources. The most significant advances in classification theory in recent decades has been as a result of efforts to improve effectiveness of indexing systems. Library classification systems are indexing languages or systems. Courses offered for the preparation of indexers in the United States and the United Kingdom are reviewed. A point of congruence for both the indexer and the library classifier would appear to be the need for a thorough preparation in the techniques of subject analysis. Any subject heading list will suffer from omissions as well as the inclusion of terms which the patron will never use. Indexing theory has provided the technical services department with methods for evaluation of effectiveness. The writer does not believe that these techniques are used, nor do current courses, workshops, and continuing education programs stress them. When theory is totally subjugated to practice, critical thinking and maximum effectiveness will suffer.

0.0065539777 = product of:
  0.039323866 = sum of:
    0.039323866 = weight(_text_:computer in 2638) [ClassicSimilarity], result of:
      0.039323866 = score(doc=2638,freq=2.0), product of:
        0.16231956 = queryWeight, product of:
          3.6545093 = idf(docFreq=3109, maxDocs=44218)
          0.044416238 = queryNorm
        0.24226204 = fieldWeight in 2638, product of:
          1.4142135 = tf(freq=2.0), with freq of:
            2.0 = termFreq=2.0
          3.6545093 = idf(docFreq=3109, maxDocs=44218)
          0.046875 = fieldNorm(doc=2638)
  0.16666667 = coord(1/6)

Abstract

Studies the quality of subject indexing by Chemical Abstracts Indexing Service by confronting authors with the particular indexing terms attributed to their computer, for 270 articles published in 54 journals, 5 articles out of each journal. Responses (80%) indicate the superior quality of keywords, both as content descriptors and as retrieval tools. Author judgements on these 2 different aspects do not always converge, however. CAS's indexing policy to cover only 'new' aspects is reflected in author's judgements that index lists are somewhat incomplete, in particular in the case of thesaurus terms (index headings). The large effort expanded by CAS in maintaining and using a subject thesuaurs, in order to select valid index headings, as compared to quick and cheap keyword postings, does not lead to clear superior quality of thesaurus terms for document description nor in retrieval. Some 20% of papers were not placed in 'proper' CA main section, according to authors. As concerns the use of indexing data by third parties, in bibliometrics, users should be aware of the indexing policies behind the data, in order to prevent invalid interpretations

0.0040118583 = product of:
  0.024071148 = sum of:
    0.024071148 = product of:
      0.048142295 = sum of:
        0.048142295 = weight(_text_:22 in 7247) [ClassicSimilarity], result of:
          0.048142295 = score(doc=7247,freq=2.0), product of:
            0.1555381 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.044416238 = queryNorm
            0.30952093 = fieldWeight in 7247, 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=7247)
      0.5 = coord(1/2)
  0.16666667 = coord(1/6)

Source

Canadian journal of information and library science. 21(1996) no.2, S.1-22

0.003510376 = product of:
  0.021062255 = sum of:
    0.021062255 = product of:
      0.04212451 = sum of:
        0.04212451 = weight(_text_:22 in 3510) [ClassicSimilarity], result of:
          0.04212451 = score(doc=3510,freq=2.0), product of:
            0.1555381 = queryWeight, product of:
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.044416238 = queryNorm
            0.2708308 = fieldWeight in 3510, product of:
              1.4142135 = tf(freq=2.0), with freq of:
                2.0 = termFreq=2.0
              3.5018296 = idf(docFreq=3622, maxDocs=44218)
              0.0546875 = fieldNorm(doc=3510)
      0.5 = coord(1/2)
  0.16666667 = coord(1/6)

Source

Health libraries review. 7(1990) no.1, S.22-26