Schubert András, Zsindely Sándor, Glänzel Wolfgang, Braun Tibor (szerk.): A tudományos publikációs tevékenység mutatószámai az MTA természettudományi, műszaki, orvostudományi és agrártudományi kutatóhelyein 1976–1980 (A MTAK Informatikai És Tudományelemzési Sorozata 2., 1982)

VII. FÜGGELÉK - 2. A „Journal Citation Reports" által nyilvántartott folyóiratok „impact factorai"

Introduction Definitions 103 These Definitions are, in some cases, actually definitions. In others, they explain usages peculiar to the SCI® and ICR" and their editorial conventions. In still others (e.g., cited journal, citing journal, times cited), the definition is meant primarily to warn the reader that, in the case of the JCR, there is more than initially meets the eye in these apparently obvious terms, and frequently more than the memory instantly discloses. The user will need a fair command of their meaning when reading the discriptions of the Citing and Cited Journal Packages. Citation. When one document (B) mentions, or refers to another document (A), the latter (A), has been cited by the former (B) as a source of information, as support for a point of view, as authority for a statement of fact, etc. The word citation is used to indicate not only the fact that document A has been cited in a reference of document B, but also for the description of document A contained in the reference (Lederberg J. J. Bad. 63:399, 1952). In this sense, citation and reference are frequently used interchangeably. Cltadon Index. The Citation Index is an alphabetic list, by first author, of items cited in references from footnotes or bibliographies of a source article. Each such citation is followed by a short bibliographic description of the source article which contained the citing reference. Cited Journal. A science journal cited by any journal in the Science Citation Index

9/Social Sciences Citation Index

9/Arts & Humanities Citation Index ™ data base. A cited journal is not necessarily a source journal covered by SCI, SSCI" otA&HCI". The Cited Journal Package may also include as cited 'journals' other nonjournal serial publications. Such entries have been retained for their informational value. Citing Journal. In the Cited Journal Package any source journal from the combined SCI/SSCI/ A&HCI data base. In the Citing Journal Package of JCR, coverage is limited to science journals covered by SCI. Hall Life. The number of journal publication years from the current year back whose articles have accounted for 50% of the total citations received in a given year. Immediacy Index. A measure of how quickly the 'average cited article' in a particular journal is cited. A journal's immediacy index considers citations made during the year in which the cited items were published. Thus, the 1979 immediacy index of Journal X would be calculated by dividing the number of all journals' 1979 citations of items it published in 1979 by the total number of source items it published in 1979. It should be obvious that an article published early in the year has a better chance of being cited than one published later in the year. As a result, journals published weekly and monthly will theoretically have an advantage, as regards immediacy, over journals published quarterly and semi-annually. Impact Factor. A measure of the frequency with which the 'average cited article' in a journal has been cited in a particular year. The JCR impact factor is basically a ratio between citations and citable items published. Thus, the 1979 impact factor of journal X would be calculated by dividing the number of all the SCI source journnals' 1979 citations of articles journal X published in 1977 and 1978 by the total number of source items it published in 1977 and 1978. There are other ways of calculating journal impact (see Garfield E. Citation analysis as a tool in journal evaluation. Science 178

:471-79, 1972; especially note 27). The impact factor is useful in evaluating the significance of absolute citation frequencies. It tends to discount the advantage of large journals over small ones, of frequently issued journals over less frequently issued ones (weeklies vs. quarterlies or annuals); of older journals over newer journals. In each such case the first is likely to produce or have produced a larger citable corpus than the second. All things being equal, the larger that corpus, the more often a journal will be cifed. The impact factor allows some qualification of quantitative data. The qualification is algorithmic and objective, but nonetheless useful in journal evaluation. Journal Tide. The title of a scientific, technical, or social sciences periodical is usually given in the