38. Bibliometric (scientometric) indicators in the system of international scientific publications: index of scientific citation and impact-factor

Nobody knows exactly, how many scientific-technical journals there are in the world. According to some estimates - about fifty thousand, to another - even more than hundred thousand. It is more difficult to count how many articles are published every year in the scientific journals, probably here we are talking about millions. Both articles and journals differ not only by thematic and language of publication, but also by the impact on the science development.

In 1960 year Eugene Garfield, the founder of the Institute of scientific information (ISI), for the first time introduced the index of scientific citation (number of citations) for literature on exact and natural sciences (Science citation index) in the same- name journal and suggested to use it as the indicator of impact of the scientific publication. In 1975 Eugene Garfield as an appendix to the "Science Citation Index" began to publish a new journal "Journal Citation Reports", in which there was suggested to estimate the impact of the scientific journals by indicator, which is calculated on the following formula:

IF = A/B,

where A - is a number of references in publications of the year on the articles published in the journal for the previous two years, B - is a total number of articles published in the journal for the previous two years.

There was suggested a name "impact factor" for the indicator. It is an evaluation of that how often there are citations for the articles published in this journal in publications of other scientific journals. In the opposite to the absolute number of references, the method suggested in the same power equalize in rights the young and old journals (only articles for the last two years are taken into account, but not for all history of the journal), the large and little journals, since the impact-factor - is an average number of references to one article, it does not depend on the number of articles in the issue and periodicity of the issue.

At an accounting of the number of articles published only articles about original investigations or review articles are taken into account. Articles like "front matter" or "news and views", which can be in the journals Nature Science, Journal of the American Medical Association, the British Medical Journal, The Lancet and some other, are not taken into account. Articles like the letters to editorials, correctness of misprints or mistakes and like that are not taken into account, but references are taken into account in all publications not depending on the type of the publications. However in the numerator there can be a number of citations not for the year, but for more long time period. In this case there appear 3-, 5- and 7-year values of the impact factor. The two most popular indicators, index of citation and impact-factor, are calculated on the base of one data-base, but Science Citation Index is an evaluation of impact of a publication or a researcher, and the impact-factor is an evaluation of impact of a journal.

In 1992 year the Institute of scientific information became the part of the corporation Thomson (now it is called Thomson Scientific), and nowadays is a part of the corporation Thomson Reuters. Impact-factor of journals are published in the journal Journal Citation Reports, which is a Now the system of citation account Thomson Scientific includes more than 9300 journals from more than 60 countries by 256 categories. It is thought that these journals cover more than 90 % of the most important information in the field of natural science, technique, medicine and agriculture. Besides, Thomson Scientific supports a platform which is called Web of Science. This platform contains a data-base which allow establishing impact-factors and indexes of citations in addition on retrospective estimation from 1900. This data-base covers not only natural and exact sciences (Science Citation Index Expanded), but also social and humanity science (Social Sciences Citation Index и Arts & Humanities Citation Index). Nowadays for the quantitative evaluation of the importance of the scientists' research, impact of articles and journals, scientific activity of regions and countries there is applied a whole complex of bibliometric indicators, such as number of publications, total number of references, citation index, index of immediate citation, articles' average life time, Hirsh index and several other. Just by these data the conclusion about state of science in a country and evaluation of contribution to science is made. Despite the many disadvantages, the impact-factors and indexes of citation got a special attention lately. By impact-factor and citation index the journals' level, quality of articles published in it are estimated, financial support for researchers is given and employees are engaged.

This is first of all refers to the west scientific community. However the bibliometric indicators gain more and more important role in Kazakhstan too. Eugene Garfield from the beginning of introduction of the impact-factor and citation index constantly warned against their indiscriminate use. To the present moment there are written a lot about problems on correct use of IF and citation index and about examples of typical mistakes. Both journal impact-factor and citation index depend on many parameters, directly not connecting with scientific activity.

Not always the number of article's citation, actually, reflects the quality of the investigation represented in it, however, as the number of publications - contribution of the researcher. Both indicators depend on the field of research, ournal type and publication. For example, the review and methodical articles have the largest index of citations; in the rating of journals the interdisciplinary and also biomedical issues take the upper positions. The time period (two years), when one takes into account citation for impact-factor calculation, is too short, since the most important or classical publications are often cited even in several decades after publication. Some very important publications begin to be cited later than in two years after their issue, and hence, such citations are not taken into account at impact-factor calculation. From other hand, an increase of the time period, in which the citations are accounted, will make the impact-factor more sensible to changes.

In addition, in journals with long time of publication there appear articles which refer to publications not included in three-year interval. Indeed, in some journals the time between accepting and publication is more than two years, thus, only one year is for references, which are taken into account in calculations.

The nature of results in the different field of research lead to different frequency of results publication, what also influences on impact-factors. Impact-factors of journals, publishing, for example, articles on ecology, are certainly lower than those of biomedical journals. That is why it is correct to compare by impact-factor journals of close scientific disciplines.

Now there exist 140 such groups. Nevertheless, for today, it is granted that IF - is one of the formal criteria, by which one can compare the level of scientific research. Such approach is based on that journals with high IF are usually characterized with hard system of peer-review, than journals with low IF (although, beyond all doubts, there exist exceptions). The last total information about impact-factors of all journals is available to subscribers of the Journal Citation Reports. Impact-factors of journals for partially available in free access on the Scientific and many others. In addition, if a journal has an impact-factor (and not all even international journals have it), then the journal impact-factor is certainly placed on one of the information page of the journal and also on the web-site of the journal.

Alternative systems of account and search for scientific publications

The system of scientific publications' account suggested by Thomson Scientific is the oldest and most famous one, but not only one. Its distinguishable peculiarity is that there are accounted only articles from peer-reviewed journals. All other types of scientific publications are not considered. Currently the Thomson Scientific system has worthy competitors and they cover not only peer-reviewed articles, but also articles' collections, monographs, conference proceedings, archives, reports and etc. Scopus - is a search platform of the company Elsevier which cover more than 20 000 peer- reviewed journals and also serial issues (books series, conference materials), which have ISSN (International Standard Serial Numbers) and patents. The total service is available for only subscribers. Cite-Seer - is the first automate free of charge system of indexing of scientific publications, which appear in 1997. It includes first of all publications on information technologies. Scirus - is a free of charge product of the company Elsevier. It allows finding the newest scientific reports, dissertations, journal articles, patents, re-prints, which are covered by other search systems. The system Google Scholar is becoming popular. The Google Scholar is a free of charge internet-searcher, which covers scientific publications of different formats and from different field of science. The Google Scholar, released in beta in November 2004, includes the most of peer-reviewed electronic journals of Europe and America from the largest scientific publishers. Its advertising slogan - "Standing on the shoulders of giants" - is a tribute to the scientists who have contributed to science over the centuries, providing the basis for new intellectual achievements. Russian index of scientific citation For inclusion in the data-bases the Thomson Scientific and Scopus select journals on certain methodic which account many qualitative and quantitative indicators of journals, articles and authors. Mainly these data-bases include journals released in English or having English version. Post-soviet journals are slightly represented in these bibliographic systems. For example, for more objective activity of the Russian scientists recently, in the end of 2006, there was developed a system, accounting the total index of citation of the Russian scientists and organizations by publication both in the leading Russian and the foreign scientific journals. For analysis of publication of the Russian scientists in the foreign and translated Russian journals the data of Thomson Scientific can be used, and for the main part of the Russian journals there created the similar mechanism of indexing of scientific articles and references in Russia - Russian Index of Scientific Citation. Enter to RISC is free of charge: it is enough to do personal registration on eLIBRARY. However, citation index, calculated by different systems can differ. It is connected with, for example, that Web of Science, accounts only publications in the peer-reviewed journals, but does not account books, which are taken into account by systems Scirus and Google Scholar.