Year : 2013 | Volume
: 31 | Issue : 3 | Page : 133--134
Appraising journals – Impact factor, citation index, …?
People’s College of Dental Sciences, Bhopal, India
N D Shashikiran
People’s College of Dental Sciences, Bhopal
|How to cite this article:|
Shashikiran N D. Appraising journals – Impact factor, citation index, …?.J Indian Soc Pedod Prev Dent 2013;31:133-134
|How to cite this URL:|
Shashikiran N D. Appraising journals – Impact factor, citation index, …?. J Indian Soc Pedod Prev Dent [serial online] 2013 [cited 2022 Jun 29 ];31:133-134
Available from: https://www.jisppd.com/text.asp?2013/31/3/133/117961
Eugene Garfield first mentioned the idea of an impact factor in Science magazine in 1955. Irving H. Sher and Eugene Garfield created the journal impact factor to help select journals for the new Science Citation Index. In his own words, "It did not occur to me that 'impact' would one day become so controversial. Like nuclear energy, the impact factor is a mixed blessing. I expected it to be used constructively while recognizing that in the wrong hands it might be abused." While Garfield's 1955 paper is considered primordial for citation indexing history, it is his 1972 paper in Science titled "Citation analysis as a tool in journal evaluation" that has received most attention from journal editors.
In 1960, Eugene Garfield's Institute for Scientific Information (ISI) introduced the first citation index for papers published in academic journals, first the Science Citation Index (SCI), and later the Social Sciences Citation Index (SSCI) and the Arts and Humanities Citation Index (AHCI). In the words of the web, a citation index is a bibliographic index with which the progress of an idea or research can be traced by searching the published works (articles, books, thesis) that cite a particular author or article.
A journal's impact factor is based on two elements: the numerator, which is the number of cites in the current year to any items published in the journal in the previous 2 years, and the denominator, the number of substantive articles published in the same 2 years. The term "impact factor" has gradually evolved to describe both journal and author impact. This ambiguity often causes problems. It is one thing to use impact factors to compare journals and quite another to use them to compare authors. Journal impact factors generally involve relatively large populations of articles and citations. Individual authors, on average, produce much smaller numbers of articles, although some are phenomenal. There is a widespread but mistaken belief that the size of the scientific community that a journal serves significantly affects the journal's impact factor. This assumption overlooks the fact that while more authors produce more citations, these must be shared by a larger number of cited articles. Most articles in most fields are not well cited, whereas some articles in small fields may have unusual impact, especially where they have cross-disciplinary impact. It is well known that there is a skewed distribution of citations in most fields. The well-known 80/20 rule applies in that 20% of articles may account for 80% of the citations. To reiterate, the key determinants in impact are not the number of authors or articles in the field but, rather, the citation density and the age of the literature cited.
The skewness of citations is repeated as a mantra by critics of the impact factor. Some authors would like to see impacts calculated solely on the basis of their most-cited papers, so that their otherwise low impact factors can be ignored. However, since most journals experience this skewness, it should not significantly affect journal rankings. Of the many conflicting opinions about impact factors, one can express the situation succinctly. "Impact factor is not a perfect tool to measure the quality of articles, but there is nothing better, and it has the advantage of already being in existence and is, therefore, a good technique for scientific evaluation. Experience has shown that in each specialty, the best journals are those in which it is most difficult to have an article accepted, and these are the journals that have a high impact factor. Most of these journals existed long before the impact factor was devised. The use of impact factor as a measure of quality is widespread because it fits well with the opinion we have in each field of the best journals in our specialty." The more notable achievement is that we really are publishing all kinds of research, regardless of its estimated impact, and letting the community decide what is worthy of citation. It is a good time to remember that it is the papers, not the journals they are published in, that make the impact.
On behalf of JISPPD, I would like to welcome each of you to the 35 th ISPPD conference. It is an exciting time for us as we continue to grow and adapt, remaining always adaptable, motivated, and responsive. Throughout this conference, I ask you to stay engaged, keep us proactive, and help us shape the future of ISPPD. My personal respect and thanks goes out to all of you.