Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2016 Mar 15;11(3):e0151414.
doi: 10.1371/journal.pone.0151414. eCollection 2016.

Journal Impact Factor: Do the Numerator and Denominator Need Correction?

Xue-Li Liu  1   2 , Shuang-Shuang Gai  2   3 , Jing Zhou  2   3
Affiliations
Comparative Study

Journal Impact Factor: Do the Numerator and Denominator Need Correction?

Xue-Li Liu et al. PLoS One. .

Abstract

To correct the incongruence of document types between the numerator and denominator in the traditional impact factor (IF), we make a corresponding adjustment to its formula and present five corrective IFs: IFTotal/Total, IFTotal/AREL, IFAR/AR, IFAREL/AR, and IFAREL/AREL. Based on a survey of researchers in the fields of ophthalmology and mathematics, we obtained the real impact ranking of sample journals in the minds of peer experts. The correlations between various IFs and questionnaire score were analyzed to verify their journal evaluation effects. The results show that it is scientific and reasonable to use five corrective IFs for journal evaluation for both ophthalmology and mathematics. For ophthalmology, the journal evaluation effects of the five corrective IFs are superior than those of traditional IF: the corrective effect of IFAR/AR is the best, IFAREL/AR is better than IFTotal/Total, followed by IFTotal/AREL, and IFAREL/AREL. For mathematics, the journal evaluation effect of traditional IF is superior than those of the five corrective IFs: the corrective effect of IFTotal/Total is best, IFAREL/AR is better than IFTotal/AREL and IFAREL/AREL, and the corrective effect of IFAR/AR is the worst. In conclusion, not all disciplinary journal IF need correction. The results in the current paper show that to correct the IF of ophthalmologic journals may be valuable, but it seems to be meaningless for mathematic journals.

PubMed Disclaimer

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Correlations between the questionnaire score and various IFs of 30 ophthalmologic journals.
Fig 2
Fig 2. Correlations between the questionnaire score and various IFs of 27 mathematical journals.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Garfield E. Citation Indexes for Science: a new dimension in documentation through association of ideas. Science. 1990; 122:108–111. - PubMed
    1. Wu XF, Fu Q, Rousseau R. On indexing in the Web of Science and predicting journal impact factor. Journal of Zhejiang University SCIENCE B. 2008; 9:582–590. 10.1631/jzus.B0840001 - DOI - PMC - PubMed
    1. Garfield E. The history and meaning of the journal impact factor. JAMA-Journal of the American Medical Association. 2006; 295:90–93. - PubMed
    1. Wan H, Tan ZY, Lu JJ, Zhu XL. Summary of the Evolution of Citation Analysis Research: 2001–2014. Library and Information Service. 2015; 59:120–136.
    1. Garfield E, Sher IH. New factors in the evaluation of scientific literature through citation indexing. American Documentation. 1963; 14(3):195–201.

Publication types

Grants and funding

This work was supported by grant number:15BTQ061 from theNational Social Science Found of China. The URLs of funder's website: http://www.npopss-cn.gov.cn/n/2015/0625/c219469-27206694.html.