MONO91 Indexes Compiled by Machine chapter Mary Elizabeth Stevens National Bureau of Standards `I changes of terminology with time, and Lipetz suggests that it can break down barriers with respect to use of foreign literature. 24 Other claimed advantages relate to the usefulness of the citation index for purposes other than those of direct literature search. Such other purposes include identification of significant research by "equating frequency of citation with relative significance of subject matter'1, (Salton, 1962 [520]), determinations of the number of references cited in a given field or by journal or publication date (Atherton, 1962 [25]), evaluation of the relative importance of various scientific journals (Westbrook, 1960 [636]; Kessler, 1961 [322]), tracing of trends in the history of ideas or in a particular field of literature 3/ (Brownson, 1963 [82]; Salton, 1962 [520]) - and empirical studies of the frequencies of self-citation, multiple authorship, and the like (Atherton, 1962 [25]). A number of disadvantages of the citation index are to be noted, however. First is the obvious lack of consistency between authors in terms of whether or not they cite the prior literature at all and in terms of the completeness and correctness of the citations they do make. 4/ Atherton quotes Westbrook as saying: "Science is subject to changing fashions of interest that lead to a distorted number of published papers in a given subject and an inordinately high level of citations to any one who reports first on the fashionable subject. The method will not appraise work performed but not published." 5/ 1/ 2/ 3/ Ibid, p.6: "Changes in terminology are to a certain extent overcome through the citation approach, since the author who makes a reference to a paper that is forty or fifty years old is making the jump in terminology for us." See also [OCRerr]arfield, 1956[212], p.11. Lipetz, 1963, [366], p. 265: "It is reasoned that availability of a citation index derived from Soviet physics journals and approachable through familar American references should stimulate utilization of the Soviet physics journals in the United States." See also Reisner, 1963 [497], p. 71: "Citation indexes are receiving increasing attention as bibliographic aids and as sociometric tools. As sociometric tools, they are being used to explore the flow of information across national boundaries and from pure to applied fields, to determine the structure of a field, and to determine the `value' of documents or authors." See, for example, Doyle, 1963 [162], p. 8: "The disadvantages of this kind of indexing is, of course, that it depends on authors providing ample and suitable references"; Salton, 1962 [520], p.111-7: "In many cases personal preferences are evident both as to number and types of papers cited; authors have varying back- grounds, and there may also exist a tendency toward self-citation regardless of relevancy"; Thompson, 1963 [600], p. Il-i: "The difficulties... are largely due to the extreme variability of format and to the lack of standardization which prevails in the publication of citations." 4/ 5/ Atherton, 1962 [25], p. 4, citing J. H. Westbrook. 32