Assess Your Research Impact

Note: Journal metrics like the Journal Impact Factor should not be used to assess researchers for funding, hiring, promotion, and tenure decisions. Research should be assessed on its own merits rather than on the basis of journals where it is published. However, an overview of the Journal Impact Factor is included in this guide because researchers might encounter this metric in the context of impact assessment, and it's helpful to know its appropriate uses and limitations.

Journal metrics are used to measure and compare the citation performance for all articles published by a journal. These metrics can be impacted by:

• Journal self-citation, when journals encourage authors to cite works previously published in the journal
• Differences in citation practices and patterns across disciplines
• Differences in citations patterns across article types (for example, review articles generally receive greater numbers of citations)
• Which sources of data are used to generate metrics (for example, which journals are included or excluded from the data set)

The Journal Impact Factor (JIF) is a proprietary metric owned and calculated by Clarivate Analytics that measures the frequency with which the “average article” in a journal has been cited in a given year.

Method of calculation

1. The number of citations received for all material published in the previous two years, 

          divided by 

2. the total number of "citable items" published in the two previous years

Calculation Example

Citations received in 2024:

• Citations of 2022 articles = 38
• Citations of 2023 articles = 67
• Total citations received in 2024: 38 + 67 = 105

Citable items published in previous two years:

• Citable items published in 2022 = 46
• Citable items published in 2023 = 44
• Total citable items published in 2022 and 2023: 46 + 44 = 90

JIF Calculation:

1. Total citations: 105
2. Total articles published: 90
3. Impact Factor (2024): 105 / 90 = 1.17

Appropriate Uses

• Comparing the relative influence of journals within a discipline, as measured by citations
• Informing library collection development decisions, which was the JIF's original intended purpose

Limitations

• The JIF is not a normalized metric, meaning it does not account for the differences in citation patterns across disciplines.
• The JIF only applies to journals indexed by Clarivate Analytics in Web of Science.
• "Citable items" included in the JIF calculation are limited to items indexed in Web of Science as articles and reviews. Items with any other document type, including editorial material, letter, and meeting abstract, are not included. Some have taken issue with the lack of transparency in defining citable items and the potential for journals to "game" the calculation.
• Non-English language journals and journals published outside of North America are underrepresented in Web of Science indexes.
• Review articles have higher average citation rates and can inflate JIF values.

Inappropriate Uses

• The JIF, along with other journal metrics, should not be used as a surrogate measure of the quality of individual research articles or to assess an individual researcher’s contributions, or in hiring, promotion, or funding decisions.
• Citation rates/patterns and Web of Science journal coverage across disciplines vary, so the JIF should not be used to compare journals across disciplines.
• For more information on the limitations and potential misuse of journal metrics, read the Declaration on Research Assessment.

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