Comparing journals from different fields of science and social science through a JCR subject categories normalized impact factor

Abstract

The journal Impact Factor (IF) is not comparable among fields of Science and Social Science because of systematic differences in publication and citation behaviour across disciplines. In this work, a decomposing of the field aggregate impact factor into five normally distributed variables is presented. Considering these factors, a Principal Component Analysis is employed to find the sources of the variance in the JCR subject categories of Science and Social Science. Although publication and citation behaviour differs largely across disciplines, principal components explain more than 78% of the total variance and the average number of references per paper is not the primary factor explaining the variance in impact factors across categories. The Categories Normalized Impact Factor (CNIF) based on the JCR subject category list is proposed and compared with the IF. This normalization is achieved by considering all the indexing categories of each journal. An empirical application, with one hundred journals in two or more subject categories of economics and business, shows that the gap between rankings is reduced around 32% in the journals analyzed. This gap is obtained as the maximum distance among the ranking percentiles from all categories where each journal is included.

Journal selection criteria in an open access environment: A comparison between the medicine and social sciences

“…The IF of the journal, a publisher's prestige, their inclusion in abstracting and indexing databases, and an online submission with tracking facility are statistically significantly more important to medical authors than to scholars in the social sciences (see Figure 2). Many studies have claimed that the IF's influence can differ widely across disciplines (Dorta-Gonzalez & Dorta-González, 2013;Scully & Lodge, 2005;Seglen, 1997). Althouse et al (2009) and Amin and Mabe (2004) have independently identified major reasons for higher IF values in medicine than in the social sciences.…”

Journal topic citation potential and between-field comparisons: The topic normalized impact factor

“…This formulation allows us to easily obtain the citation potential of the JCR database, which is 2.822 in year 2011 (Dorta-González & Dorta-González, 2013a). It also allows us to calculate, in a similar way, the citation potential in any set of journals (as discussed below).…”

“…Garfield (1979) proposes the term 'citation potential' for systematic differences among fields of science, based on the average number of references. For example, in the biomedical fields long reference lists with more than fifty items are common, but in mathematics short lists with less than twenty references are the standard (Dorta-González & Dorta-González, 2013a). These differences are a consequence of the citation cultures and can produce significant differences in the JIF, since the probability of being cited is affected.…”

A Novel Journal Evaluation Metric that Adjusts the Impact Factors across Different Subject Categories

“…However Brody agreed that impact factor is imperfect but not yet replaceable, because substantial alternatives has no clear improvements over IF as a single measure (Brody, 2013). In response to critics, Thomson Reuters supple-mented more indicators: Five year impact factor, Eigenfactor score, Article Influence Score in the online version of JCR (Dorta-Gonzalez and Dorta-Gonzalez, 2012). Also there has been approach to apply rank normalization to solve Vanclay's dilemma with impact factor (Pudovkin and Garfield, 2012).…”