Journal Impact Factor based on the date of electronic publication
From The Embassy of Good Science
ThemesJournal Impact Factor based on the date of electronic publication
What is this about?
Calculation of journal’s Impact Factor (IF) is based on the date of print publication even though articles are available online and can be cited. This creates problems in citation record leading to artificial increase of IFs. From now on Clarivate Analytics, which issues IFs through Journal Citation Reports (JCR), will calculate IFs based on the date of electronic publication.
Why is this important?
Although online publication dates back to the mid-1990s, a journal’s IF is calculated based on print publication. Articles are available in electronic form prior to their print publication and the time between is called “online-to-print lag”.[1] This lag is short for some articles, but it can prolong for months or even years for others.[2] Since papers available online can be cited immediately and impact factor calculation is based upon their publication in print, this time frame between gives them a greater chance of being cited in the 2-year window compared to articles with no online-to-print lag.[1] Also, an article published online at the end of a year can be published in print in the next year.[3] For instance, if a paper is published online in December 2019 and in print in January 2020, one author may cite the paper as being published in 2019 and another in 2020.[2] Longer online exposure before the beginning of the citation counting can lead to a higher number of citations, which means online-to-print lags might artificially increase journals’ IFs.[1][3][4][5]
For whom is this important?
What are the best practices?
A study analyzed 61 neuroscience journals from 2003 to 2011. The aim was to find out whether there was an increase in publication delay over one decade and whether this phenomenon can increase IFs. The study showed that while for most journals in 2003 the phenomenon of online-to-print lag did not exist, about 50% of the studied journals from 2011 had online-to-print lag greater than 3 months. The lag varied between journals ranging from 0 to 19 months.[1] There was an increase of lags over one decade, which subsequently raised the journals IF. Moreover, the larger the online-to-print lag, the higher the increase of IF.[1]
This is why some researchers suggested that the date of the online publication should be used to calculate the IF and not the date of the print publication.[1][6] In the fall of 2020 Clarivate Analytics announced that it would make this shift.[2] This change will help reduce ambiguity and contribute to more transparent calculation of citation metrics.[2] The 2021 release using 2020 data is planned to be the transition year and the full switch will begin in 2022 using 2021 publication data.[2]Andrijana Perković Paloš contributed to this theme. Latest contribution was Jun 11, 2021
Other information
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- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Tort Adriano B L. Rising Publication Delays Inflate Journal Impact Factors. PLOS ONE. 2012;7(12): e53374.
- ↑ 2.0 2.1 2.2 2.3 2.4 Davis P. Changes to Journal Impact Factor Announced for 2021. The Scholarly Kitchen. 2020 Dec 7. [cited 2021 March 5]. Available from: https://scholarlykitchen.sspnet.org/2020/12/07/jif-calculation-2021/.
- ↑ 3.0 3.1 Davis P. Does Post-Dating Publication Help Journal Impact Factors? The Scholarly Kitchen. 2012 April 2. [cited 2021 March 5]. Available from: https://scholarlykitchen.sspnet.org/2012/04/02/does-post-dating-publication-helps-journal-impact-factors/.
- ↑ Krell F T. Academic publishers’ time-loop: another mechanism to manipulate impact factors? Learned publishing. 2012;25(2): 153-154.
- ↑ Haustein S, Bowman T D, Costas R. When is an article actually published? An analysis of online availability, publication, and indexation dates. arXiv.org. 2015 May 4. [cited 2021 March 5]. Available from: https://arxiv.org/ftp/arxiv/papers/1505/1505.00796.pdf.
- ↑ Haustein S, Bowman T D, Costas R. When is an article actually published? An analysis of online availability, publication, and indexation dates. arXiv.org. 2015 May 4. [cited 2021 March 5]. Available from: https://arxiv.org/ftp/arxiv/papers/1505/1505.00796.pdf.
