Reasons for Journal Impact Factor Changes: Influence of Changing Source Items

Abstract

Both the concept and the application of the impact factor (IF) have been subject to widespread critique, including concerns over its potential manipulation. This study provides a systematic analysis of significant journal Impact Factor changes, based on the relative contribution of either one or both variables of the IF equation (i.e. citations / articles as the numerator / denominator of the quotient). A cohort of JCR-listed journals which faced the most dramatic absolute IF changes between 2013 and 2014 (ΔIF ≥ 3.0, n = 49) was analyzed for the causes resulting in IF changes that theses journals have experienced in the last five years. Along with the variation by number of articles and citations, this analysis includes the relative change of both variables compared to each other and offers a classification of `valid`and `invalid`scenarios of IF variation in terms of the intended goal of the IF to measure journal quality. The sample cohort features a considerable incidence of IF increases (18%) which are qualified as `invalid`according to this classification because the IF increase is merely based on a favorably changing number of articles (denominator). The results of this analysis point out the potentially delusive effect of IF increases gained through effective shrinkage of publication output. Therefore, careful consideration of the details of the IF equation and possible implementation of control mechanisms versus the volatile factor of number of articles may help to improve the expressiveness of this metric.

The Effect of Gender in the Publication Patterns in Mathematics

“…It is defined as the average number of article citations in a journal in the last two years. There is widespread criticism of the impact factor, as there are many means to manipulate it [30]. Based on different publication and citation practices in various academic fields, it is difficult to compare the impact factor across disciplines.…”

Journals that Rise from the Fourth Quartile to the First Quartile in Six Years or Less: Mechanisms of Change and the Role of Journal Self-Citations

“…Different mechanisms underlie the quartile transitions (see the work by Kiesslich, Weineck, and Koelblinger for a detailed discussion [52]). For example, some transitions in Box 1 involved increases both in the number of citations used to compute the JIF (JIF numerator) and the number of citable items (JIF denominator).…”

Quality Assurance in journal editorial processes

“…The change in impact factor (and similar metrics) over time can give insights into the perceived quality or usefulness of a journal although this can be affected by other factors, not least changes in the scope of the articles published in the journal (see [5]). As an example, for some years, the British Journal of Educational Technology included a section of short articles that were intended to give advance news of research in progress.…”