Impact Factor


Journal Citation Reports (JCR) is a tool that keeps track of the numbers of citations to articles published in top-tier scholarly journals in the hard and social sciences. You can use the impact factor of a journal as an indicator of how important that journal is to people in a scholarly community.

What is impact factor?

Impact factor is a way of measuring the number of citations articles in a given academic journal receive on average. It is calculated by dividing the number of article citations by the total number of articles that could be cited from a particular journal. It is used as an indicator of the importance of a journal in a field, with journals with higher impact factors being more important.

Why am I having problems finding some journals using JCR?

Generally, JCR only indexes the top journals in a discipline, so this may mean that the journal in which you article is published has a lower profile in its discipline. It also can mean that the journal serves a niche expert audience, has a very specific subject matter, or serves a small subfield. In these cases, it may be best journal for your purposes, even though it is not one of the top journals in its discipline.

  1. Locate JCR on the library website. Simply search for "Journal Citation Reports" in the Search Database Titles & Descriptions field on the Articles & more tab.

  2. Collect Journal Articles you are working with.

  3. Click in the "Go to Journal Profile" search box and type the title of a journal.

  4. Click the correct title in the hints window beneath the search box.

  5. Find the column that says journal impact factor. Write this down and compare it to the impact factors of other journals in the discipline or the median impact factor in the discipline. Since different disciplines and subfields have differing citation practices, impact factor is generally a poor way to compare the influence of journals with different subject matters.

  6. Examine the other indicators of impact. The information in these other columns can also be used to understand the relative impacts of journals in a discipline or subfield.

  7. Click the link to Ulrich's Serials Directory. UlrichsWeb allows you to quickly find out other important information about a periodical, including the publisher, how frequently it is published, its target demographics, and how widely it is distributed.

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Other Indicators of Impact

Impact factor is not the only indicator of impact provided by JCR. Each column in a journal entry represents a different way of evaluating impact. Because the value of information in a discipline differs according to how it is produced, disseminated, and used by members of a scholarly community, comparing the different indicators of several journals can help you better understand their relative importance.

What is journal rank?

The rank enables you to sort the list of journals in a field by impact factor, immediacy index, and other measures of impact, influence, and prestige. This makes comparing journals within a discipline or field easier.

What is eigenfactor?

Like impact factor, the eigenfactor score measures the number of citations to a journal; unlike impact factor, the eigenfactor weights citations from important journals more heavily than those from unimportant journals, providing an arguably better metric for evaluating a journal.

What is the immediacy index?

The immediacy index measures how frequently articles in a journal are cited in the year that they are published; this offers a proxy measure for how urgent the research published in a journal is to scholars. This is especially important in fields that make rapid advances with significant material impacts. For instance, immediacy index can be important in many medical and technology-related fields.

What is the article influencer score?

The article influencer score measures how influential articles published in a journal are over the course of the five years after publication. Scores above 1.0 are for journals with above average 5-year influence, while scores below 1.0 are for journals with below average 5-year influence.

Words of Caution

Citation metrics are imperfect. The best way to evaluate importance is through experience and familiarity with a field. Also be aware that citation behaviors differ substantially between subfields and may not be particularly important in some areas of study.

Ultimately, when researching, the most important thing to figure out is whether articles make substantial contributions to the scholarly conversations relevant to your research question.

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Additional Questions and Help

If you have trouble or questions about the citation metrics, ask a librarian.

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Creative Commons License

Impact Factor is licensed under a Creative Commons Attribution 4.0 International License.