Metrics Beyond the Impact Factor — When to Use CiteScore, SJR, JCI and the h-index
A journal's web page typically lists CiteScore, SJR and SNIP alongside its Impact Factor (IF). Grant applications and research assessment exercises increasingly ask you to "consider metrics other than the IF" as well. Knowing what each one actually measures keeps the picture clear.
Journal-level metrics
| Metric | Provider | Citation window | Characteristics |
|---|---|---|---|
| Journal Impact Factor (JIF) | Clarivate (Web of Science) | 2 years | The best known of all; the denominator counts only "citable items" |
| 5-year JIF | Clarivate | 5 years | Suited to fields where citations accumulate slowly |
| Journal Citation Indicator (JCI) | Clarivate | 3 years | Field-normalised; 1.0 is the world average, 2.0 is twice the average |
| CiteScore | Elsevier (Scopus) | 4 years | All document types count in the denominator; freely available |
| SJR (SCImago Journal Rank) | SCImago (Scopus data) | 3 years | Weights citations by the standing of the citing journal; freely available |
| SNIP | CWTS Leiden (Scopus data) | 3 years | Normalised to the citation density of the field |
Why the JIF and CiteScore differ for the same journal
It is common for a single journal to have an IF of 5.0 and a CiteScore of 8.0. CiteScore covers four years of publications and counts editorials and letters in its denominator, so it tends to run higher than the IF. Scopus also indexes more journals than Web of Science and therefore captures a wider pool of citing sources. A high CiteScore does not automatically mean a high IF, so when you compare journals, compare like with like.
The JCI crosses field boundaries
Introduced by Clarivate in 2021, the JCI is normalised for field, publication year and document type, with 1.0 representing the world average. Its advantage is that it puts an emergency medicine journal and an oncology journal on the same footing: a JCI of 1.5 means a journal is cited 1.5 times as often as the average for its field. A journal with a low IF but a high JCI is one that is well regarded within its own field.
Which metrics are free to look up
The JIF and JCI require a Journal Citation Reports (JCR) subscription, but CiteScore is shown on each journal's Scopus page and SJR can be checked free of charge on the <a href="https://www.scimagojr.com/" target="_blank" rel="noopener">SCImago</a> site. When you want a sense of where a journal stands and no IF is available, the SJR quartile is a workable substitute.
Author-level metrics
| Metric | Meaning | Points to watch |
|---|---|---|
| h-index | The largest h such that h papers have each been cited h or more times | Depends heavily on career length; poorly suited to comparing early-career researchers |
| Total citations | The sum of citations across all of an author's papers | Easily dominated by a single highly cited paper |
| i10-index | The number of papers cited 10 or more times | Displayed by Google Scholar; convenient, but varies widely by field |
The h-index takes a different value in Web of Science, Scopus and Google Scholar. Google Scholar gives the largest figure because it also picks up citations from dissertations and conference abstracts. When you quote the number in an application, state which database it comes from.
Article-level metrics
For individual papers, Altmetric — a score aggregating mentions on social media, in the news and in guidelines — has come into use alongside the citation count. Clinically oriented research can have a high Altmetric score despite few citations, which makes it a useful gauge of public attention. Attention and quality, however, are not the same thing.
Living with metrics
Since DORA (the San Francisco Declaration on Research Assessment) in 2012, the principle that the IF should not be used to evaluate individuals or individual papers has spread internationally. In Japan, a growing number of institutions no longer ask for IF values in grant applications. In practice, though, the IF and quartile are still frequently consulted in promotion and degree decisions, so the realistic stance is to understand what each metric means and use it appropriately where it is needed.
This site provides only the IF and quartile, but once you have narrowed down your target journals, do also look at each journal's CiteScore and SJR, and at the kind of papers it publishes.