In June, Clarivate, an analytics giant in academic publishing, launched the 2021 update to its Journal Citation Reports (JCR) along with a new metric called Journal Citation Indicator. Most of us are familiar with JCR’s Journal Impact Factor (JIF), which has become a standard measure of the citation impact of a journal and is referred to by the scholarly community to assess the quality, reach, and integrity of sources of research content. So why the need for another metric?
Here are five things you need to know to understand this new metric: what it is, how it works, where it’s located, its potential benefits, and its drawbacks.
1. What is the Journal Citation Indicator?
The Journal Citation Indicator (JCI) is a single measurement of the field-normalized citation impact of journals in the Web of Science Core Collection across disciplines. The key words here are that the metric is normalized and cross-disciplinary. Designed to complement the JIF, the JCI controls for variables such as subject field, document type, and year of publication to provide a research field-normalized citation impact for papers published by a journal in the recent three-year period.
In other words, while the JIF is used for comparing the citation impact of journals within a discipline, the JCI provides a single number that represents journal citation impact across adjacent research fields.
2. How does the Journal Citation Indicator work?
As explained by Martin Szomszor, Director of the Institute for Scientific Information at Clarivate, the JCI uses another Clarivate metric tool, the Category Normalized Citation Impact (CNCI) to calculate an impact value for all journals in the Web of Science Core Collection, including those that do not have a JIF. The resulting number is relative to a global average baseline of 1.0. This means that a journal given a value higher than 1.0 has a higher-than-average citation impact and a journal with a value less than 1.0 has a lower-than-average citation impact.
3. Where can the Journal Citation Indicator value be found?
The release of the 2021 Journal Citation Reports includes the JCI roll-out. Even users without a paid subscription can find a journal’s JCI value for free by searching Clarivate’s online Master Journal List. For example, I searched for Cell and then clicked on “View Profile Page.” Scrolling down a bit, I found a large box highlighting the “New Metric” JCI, with values provided for 2020 and 2019, which were 7.09 and 7.17, respectively, for Cell.
4. What are the potential benefits of the Journal Citation Indicator?
Clarivate highlights a couple key contributions—in addition to field normalization—that distinguish the JCI from the JIF. First, it calculates a value from the most recent three years of publication up to the end of the current year as opposed the two years used for the JIF. Second, the full range of journals in Clarivate’s Core Collection will be given a JCI value, whereas not all journals receive a JIF value. This will give users a broader understanding of the impact of their publications and intends to enable an easy and fair comparison of citation impact between disciplines.
5. What are the limitations of the Journal Citation Indicator?
For a clear explanation of the limitations of the Journal Citation Indicator, I direct you to an article by Phil Davis posted on the Society for Scholarly Publishing’s Scholarly Kitchen blog: “Journal Citation Indicator. Just Another Tool in Clarivate’s Metrics Toolbox?” Davis points out that field normalization is difficult to achieve, and he cautions against the JCI’s reliance on the fixed subject-area categories of Clarivate’s classification system. Interpretation of any metric requires judgment of context and variables. Even Clarivate advises that the JCI is not suitable for comparing journals in sharply different disciplines.
Of course, the significance of this new metric and its reception within the scholarly research and publications community remains to be seen. Will it play a major role in journal evaluation along with the JIF? Will it evolve to replace the JIF in significance within the research community? We’ll stay tuned.