Search (10 results, page 1 of 1)

  • × author_ss:"Ellis, D."
  1. Ellis, D.; Furner-Hines, J.; Willett, P.: Measuring the degree of similarity between objects in text retrieval systems (1993) 0.09
    0.09426273 = sum of:
      0.06671165 = product of:
        0.20013495 = sum of:
          0.20013495 = weight(_text_:objects in 6716) [ClassicSimilarity], result of:
            0.20013495 = score(doc=6716,freq=6.0), product of:
              0.3279419 = queryWeight, product of:
                5.315071 = idf(docFreq=590, maxDocs=44218)
                0.061700378 = queryNorm
              0.6102756 = fieldWeight in 6716, product of:
                2.4494898 = tf(freq=6.0), with freq of:
                  6.0 = termFreq=6.0
                5.315071 = idf(docFreq=590, maxDocs=44218)
                0.046875 = fieldNorm(doc=6716)
        0.33333334 = coord(1/3)
      0.02755108 = product of:
        0.05510216 = sum of:
          0.05510216 = weight(_text_:work in 6716) [ClassicSimilarity], result of:
            0.05510216 = score(doc=6716,freq=2.0), product of:
              0.22646447 = queryWeight, product of:
                3.6703904 = idf(docFreq=3060, maxDocs=44218)
                0.061700378 = queryNorm
              0.2433148 = fieldWeight in 6716, product of:
                1.4142135 = tf(freq=2.0), with freq of:
                  2.0 = termFreq=2.0
                3.6703904 = idf(docFreq=3060, maxDocs=44218)
                0.046875 = fieldNorm(doc=6716)
        0.5 = coord(1/2)
    
    Abstract
    Describes the use of a variety of similarity coefficients in the measurement of the degree of similarity between objects that contain textual information, such as documents, paragraphs, index terms or queries. The work is intended as a preliminary to future investigation of the calculations involved in measuring the degree of similarity between structured objects that may be represented by graph theoretic forms. Descusses the role of similarity coefficients in text retrieval in terms of: document and query similarity; document and document similarity; cocitation analysis; term and term similarity; and the similarity between sets of judgements, such as relevance judgements. Describes several methods for expressing the formulae used to define similarity coefficients and compares their attributes. Concludes with details the characteristics of similarity coefficients; equivalence and monotonicity; consideration of negative matches; geometric analyses; and the meaning of correlation coefficients
  2. Ellis, D.; Furner-Hines, J.; Willett, P.: On the creation of hypertext links in full-text documents : measurement of inter-linker consistency (1994) 0.03
    0.027796518 = product of:
      0.055593036 = sum of:
        0.055593036 = product of:
          0.1667791 = sum of:
            0.1667791 = weight(_text_:objects in 7493) [ClassicSimilarity], result of:
              0.1667791 = score(doc=7493,freq=6.0), product of:
                0.3279419 = queryWeight, product of:
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.061700378 = queryNorm
                0.508563 = fieldWeight in 7493, product of:
                  2.4494898 = tf(freq=6.0), with freq of:
                    6.0 = termFreq=6.0
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=7493)
          0.33333334 = coord(1/3)
      0.5 = coord(1/2)
    
    Abstract
    In important stage in the process of retrieval of objects from a hypertext database is the creation of a set of inter-nodal links that are intended to represent the relationships existing between objects; this operation is often undertaken manually, just as index terms are often manually assigned to documents in a conventional retrieval system. Studies of conventional systems have suggested that a degree of consistency in the terms assigned to documents by indexers is positively associated with retrieval effectiveness. It is thus of interest to investigate the consistency of assignment of links in separate hypertext versions of the same full-text document, since a measure of agreement may be related to the subsequent utility of the resulting hypertext databases. The calculation of values indicating the degree of similarity between objects is a technique that has been widely used in the fields of textual and chemical information retrieval; in this paper we describe the application of arithmetic coefficients and topological indices to the measurement of the degree of similarity between the sets of inter-nodal links in hypertext databases. We publish the results of a study in which several different of links are inserted, by different people, between the paragraphs of each of a number of full-text documents. Our results show little similary between the sets of links identified by different people; this finding is comparable with those of studies of inter-indexer consistency, where it has been found that there is generally only a low level of agreement between the sets of idenx terms assigned to a document by different indexers
  3. Ellis, D.: New horizons in information retrieval (1990) 0.02
    0.022959232 = product of:
      0.045918465 = sum of:
        0.045918465 = product of:
          0.09183693 = sum of:
            0.09183693 = weight(_text_:work in 815) [ClassicSimilarity], result of:
              0.09183693 = score(doc=815,freq=2.0), product of:
                0.22646447 = queryWeight, product of:
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.061700378 = queryNorm
                0.40552467 = fieldWeight in 815, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.078125 = fieldNorm(doc=815)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Footnote
    Rez. in: Canadian library journal. 48(1991) S.434 (E. Frick): "The book is full of information about the development of concepts and systems in this most fascinating part of professional work"
  4. Ellis, D.; Furner, J.; Willett, P.: On the creation of hypertext links in full-text documents : measurement of retrieval effectiveness (1996) 0.02
    0.022695763 = product of:
      0.045391526 = sum of:
        0.045391526 = product of:
          0.13617457 = sum of:
            0.13617457 = weight(_text_:objects in 4214) [ClassicSimilarity], result of:
              0.13617457 = score(doc=4214,freq=4.0), product of:
                0.3279419 = queryWeight, product of:
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.061700378 = queryNorm
                0.41523993 = fieldWeight in 4214, product of:
                  2.0 = tf(freq=4.0), with freq of:
                    4.0 = termFreq=4.0
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=4214)
          0.33333334 = coord(1/3)
      0.5 = coord(1/2)
    
    Abstract
    An important stage in the process or retrieval of objects from a hypertext database is the creation of a set of internodal links that are intended to represent the relationships existing between objects; this operation is often undertaken manually, just as index terms are often manually assigned to documents in a conventional retrieval system. In an earlier article (1994), the results were published of a study in which several different sets of links were inserted, each by a different person, between the paragraphs of each of a number of full-text documents. These results showed little similarity between the link-sets, a finding that was comparable with those of studies of inter-indexer consistency, which suggest that there is generally only a low level of agreement between the sets of index terms assigned to a document by different indexers. In this article, a description is provided of an investigation into the nature of the relationship existing between (i) the levels of inter-linker consistency obtaining among the group of hypertext databases used in our earlier experiments, and (ii) the levels of effectiveness of a number of searches carried out in those databases. An account is given of the implementation of the searches and of the methods used in the calculation of numerical values expressing their effectiveness. Analysis of the results of a comparison between recorded levels of consistency and those of effectiveness does not allow us to draw conclusions about the consistency - effectiveness relationship that are equivalent to those drawn in comparable studies of inter-indexer consistency
  5. Ellis, D.; Ford, N.; Furner, J.: In search of the unknown user : indexing, hypertext and the World Wide Web (1998) 0.02
    0.022467656 = product of:
      0.044935312 = sum of:
        0.044935312 = product of:
          0.13480593 = sum of:
            0.13480593 = weight(_text_:objects in 4714) [ClassicSimilarity], result of:
              0.13480593 = score(doc=4714,freq=2.0), product of:
                0.3279419 = queryWeight, product of:
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.061700378 = queryNorm
                0.41106653 = fieldWeight in 4714, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.0546875 = fieldNorm(doc=4714)
          0.33333334 = coord(1/3)
      0.5 = coord(1/2)
    
    Abstract
    For the purposes of this article, the indexing of information is interpreted as the pre-processing of information in order to enable its retrieval. The definition thus spans a dimension extending from classification-based approaches (pre-co-ordinate) to keyword searching (post-co-ordinate). In the first section we clarify our use of terminology, by briefly describing a framework for modelling IR systems in terms of sets of objects, relationships and functions. In the following 3 sections, we discuss the application of indexing functions to document collections of 3 specific types: (1) 'conventional' text databases; (2) hypertext databases; and (3) the World Wide Web, globally distributed across the Internet
  6. Ellis, D.; Vasconcelos, A.: ¬The relevance of facet analysis for World Wide Web subject organization and searching (2000) 0.02
    0.019481555 = product of:
      0.03896311 = sum of:
        0.03896311 = product of:
          0.07792622 = sum of:
            0.07792622 = weight(_text_:work in 2477) [ClassicSimilarity], result of:
              0.07792622 = score(doc=2477,freq=4.0), product of:
                0.22646447 = queryWeight, product of:
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.061700378 = queryNorm
                0.3440991 = fieldWeight in 2477, product of:
                  2.0 = tf(freq=4.0), with freq of:
                    4.0 = termFreq=4.0
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.046875 = fieldNorm(doc=2477)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Different forms of indexing and search facilities available on the Web are described. Use of facet analysis to structure hypertext concept structures is outlined in relation to work on (1) development of hypertext knowledge bases for designers of learning materials and (2) construction of knowledge based hypertext interfaces. The problem of lack of closeness between page designers and potential users is examined. Facet analysis is suggested as a way of alleviating some difficulties associated with this problem of designing for the unknown user.
    This is a revised version of the earlier article by Ellis and Vasconcelos (1999) (see Not Relevant, below), though that is not indicated, and much of it is identical, word for word. There is a new section covering the work of Elizabeth Duncan, which is useful and informative, but the reader is better advised to go to the originals if available.
  7. Ellis, D.; Furner-Hines, J.; Willett, P.: ¬The creation of hypertext links in full-text documents (1994) 0.02
    0.019257993 = product of:
      0.038515985 = sum of:
        0.038515985 = product of:
          0.11554795 = sum of:
            0.11554795 = weight(_text_:objects in 1084) [ClassicSimilarity], result of:
              0.11554795 = score(doc=1084,freq=2.0), product of:
                0.3279419 = queryWeight, product of:
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.061700378 = queryNorm
                0.35234275 = fieldWeight in 1084, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  5.315071 = idf(docFreq=590, maxDocs=44218)
                  0.046875 = fieldNorm(doc=1084)
          0.33333334 = coord(1/3)
      0.5 = coord(1/2)
    
    Abstract
    An important stage in the process of retrieval of objects from a hypertext database is the creation of a set of internodal links that are intended to represent the relationships existing between objetcs; an operation that is usually undertaken manually such as the allocation of subject index terms to documents. Reports results of a study in which several different sets of hypertext links were inserted, each by a different person, between the paragraphs of each of a number of full text documents. The similarity between the members of each pair of link sets was then evaluated. Results indicated that little similarity existed among the link sets, a finding comparable with those of studies of inter indexer consistency, which suggests that there is generally only a low level of agreemenet between the sets of index terms assigned to a document by indexers. Concludes with that part of the study designed to test the validity of making these kinds of assumptions in the context of hypertext link sets
  8. Ellis, D.: Progress and problems in information retrieval (1996) 0.02
    0.0167191 = product of:
      0.0334382 = sum of:
        0.0334382 = product of:
          0.0668764 = sum of:
            0.0668764 = weight(_text_:22 in 789) [ClassicSimilarity], result of:
              0.0668764 = score(doc=789,freq=2.0), product of:
                0.21606421 = queryWeight, product of:
                  3.5018296 = idf(docFreq=3622, maxDocs=44218)
                  0.061700378 = queryNorm
                0.30952093 = fieldWeight in 789, 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=789)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Date
    26. 7.2002 20:22:46
  9. Spink, A.; Wilson, T.D.; Ford, N.; Foster, A.; Ellis, D.: Information seeking and mediated searching : Part 3: successive searching (2002) 0.01
    0.011479616 = product of:
      0.022959232 = sum of:
        0.022959232 = product of:
          0.045918465 = sum of:
            0.045918465 = weight(_text_:work in 5242) [ClassicSimilarity], result of:
              0.045918465 = score(doc=5242,freq=2.0), product of:
                0.22646447 = queryWeight, product of:
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.061700378 = queryNorm
                0.20276234 = fieldWeight in 5242, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=5242)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    In "Part 3. Successive Searching.'' where Spink is the primary author, after a review of the work on successive searching, a portion of the Texas generated data is reviewed for insights on how frequently successive searching occurred, the motivation for its occurrence, and any distinctive characteristics of the successive search pattern. Of 18 mediated searches, half requested a second search and a quarter a third search. All but one seeker reported a need to refine and enhance the previous results. Second searches while characterized as refinements included a significantly higher number of items retrieved and more search cycles. Third searches had the most cycles but less retrieved items than the second. Number of terms utilized did not change significantly and overlap was limited to about one in five terms between first and second searches. No overlap occurred between the second and third searches. Problem solving stage shifts did occur with 2 moving to a later stage after the first search, 5 remaining in the same stage and one reverting to a previous stage. Precision did not increase over successive searches, but partial relevant judgments decreased between the second and third search.
  10. Foster, A.E.; Ellis, D.: Serendipity and its study (2014) 0.01
    0.011479616 = product of:
      0.022959232 = sum of:
        0.022959232 = product of:
          0.045918465 = sum of:
            0.045918465 = weight(_text_:work in 1794) [ClassicSimilarity], result of:
              0.045918465 = score(doc=1794,freq=2.0), product of:
                0.22646447 = queryWeight, product of:
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.061700378 = queryNorm
                0.20276234 = fieldWeight in 1794, product of:
                  1.4142135 = tf(freq=2.0), with freq of:
                    2.0 = termFreq=2.0
                  3.6703904 = idf(docFreq=3060, maxDocs=44218)
                  0.0390625 = fieldNorm(doc=1794)
          0.5 = coord(1/2)
      0.5 = coord(1/2)
    
    Abstract
    Purpose - The purpose of this paper is to explore the concept of serendipity and approaches to its study particularly in relation to information studies. Design/methodology/approach - The origins of the term serendipity are described and its elaboration as an exploratory and explanatory concept in science and the social sciences are outlined. The distinction between serendipity and serendipity pattern is explained and theoretical and empirical studies of both serendipity and the serendipity patterns are explored. The relationship between information encountering is described. Empirical studies of serendipity using Citation Classics and other research approaches in information studies are described. Findings - The discrepancy between occurrences of serendipity in studies using Citation Classics and reported serendipity in philosophy of science, research anecdotes, information encountering and information seeking by inter-disciplinary researchers is highlighted. A comparison between a process model of serendipity and serendipity as an emergent behavioural characteristic are indicates directions for future research. Originality/value - The paper provides and original synthesis of the theoretical and empirical literature on serendipity with particular reference to work in information studies and an indication of the methodological difficulties involved in its study.