Journal Impact Factor (JIF) shows the average number of times articles from a journal published in the past two years that have been cited in the JCR year. This is how Journal IF of 2019 is calculated:
Calculation of Journal Impact Factor in the Year 2019:
| IF in 2019 = | No. of citations received in 2019 from all items published in 2017 and 2018 |
| No. of articles & reviews published in 2017 and 2018 |
e.g.
The calculation is based on citations, hence publications in journals with higher IF may have higher chance of being cited as compared to publications published in journals with relatively lower IF.
► Note:
The Journal Citation Indicator (JCI) is the average Category Normalized Citation Impact (CNCI) of citable items (articles & reviews) published by a journal over a recent three year period. The average JCI in a category is 1. Journals with a JCI of 1.5 have 50% more citation impact than the average in that category. It may be used alongside other metrics to help you evaluate journals.
For example:
| JCI = 1.5 ►The average JCI in a category is 1. Journals with a JCI of 1.5 have 50% more citation impact than the average in that category. |
► Note:
The JCI is a normalized indicator and is not category dependent, journals in multiple categories will have a single JCI. The average JCI of any category is approximately 1.
The 5-year Impact Factor is the average number of times articles from a journal published in the last five years have been cited in the JCR year (as compared to the last 2 years for IF).
Calculation of 5-Year Impact Factor in the Year 2019:
| 5-Year IF in 2019 = | No. of citations to all items published in 2014-2018 |
| No. of articles & reviews published in 2014-2018 |
► Advantage of 5-year Impact Factor
The calculation of the 5-year Impact Factor includes a longer time span which allows more citation activities. It may be more appropriate for subject disciplines such as Arts and Humanities which take longer time to have the citation activities.
Eigenfactor Score:
Article Influence Score:
The mean of Article Influence Score for each article is 1.00. A score greater than 1.00 indicates that each article in the journal has above-average influence. A score less than 1.00 indicates that each article in the journal has below-average influence.
Read Eigenfactor Score and Article Influence Score: Detailed methods to know how these factors are calculated.
► Advantage of Eigenfactor Score and Article Influence Score
They allow comparison across subject disciplines.
Scholarly references join journals together in a vast network of citations. The Eigenfactor score and the Article Influence score are calculated by the structure of the entire network (instead of purely local citation information) to evaluate the importance of each journal so it automatically accounts for the differences in citation activities across subject disciplines and allows better comparison across research areas.
They are more suitable for research areas which take longer time to have citation activities.
In many research areas, articles are not frequently cited until several years after publication. The Eigenfactor score and the Article Influence score are calculated based on the citations received over a five year period, thus it may be more applicable to the research areas which take longer time to accumulate citation activities.
Find Impact Factor for a specific journal:
► Step 1. Go to Journal Citation Reports (JCR).
► Step 2. Type in the journal title and click on the journal title. While typing, the platform will auto-suggest the journals that match your search.
► Step 3. You will be directed to the journal's profile page. On this page, you will read the latest IF, and the subject categories this journal falls in. Clicking on the subject category will bring you to the journal's ranking in this subject category.
To check IFs of previous years, click "All Years" and read the Journal Impact Factor column.
Check journal ranking by IF in a specific subject category:
► Step 1. Go to Journal Citation Reports (JCR).
► Step 2. Click "Browse Journals".
► Step 3. Click Filter and select “Categories”. Type in/ select a subject category (or multiple categories), e.g. Energy & Fuels. You may also limit results to only those journals listed in certain quartile(s) of their subject area, e.g. Q1 (the top 25%).
On the right you will see a list of journals ranked by Impact Factor (by default), in the selected subject area. In this example, only Q1 journals (the top 25%) in the subject category Energy & Fuels will be shown.
Save favourite journals for future use & Compare journals:
After you have identified some journals, you may save them in a list for easy comparison. Saved lists can also be very helpful if you need to check the metrics of these journals on a regular basis.
► Step 1. Go to Journal Citation Reports (JCR) and sign in (from top right corner). Note that you may use your Clarivate credential (e.g. Web of Science, EndNote, Publons) to sign in.
► Step 2. Select the journal(s) you are interested. Then click "Add to Favorites list". Refer to Find IF by Journal Title or Check Journal Ranking in Subject Category tab to learn how to select journals in JCR.
► Step 3. Enter name of a new list, or select an existing list from your saved lists. Then click "Add favorites".
► Step 4. Click "Add Lists" icon at the top right corner. You will then find all saved lists of journals. You may edit the name of the list or delete the list from this page.
► Step 5. Go back to the Browse Journals page, select up to 4 journals to compare in terms of IF, ranking and subject categories...etc.
Apart from Journal Impact Factor, Journal Citation Reports provide other metrics such as JCI, Eigenfactor, JIF Quartile. Refer to other parts of the guide to know more about these metrics.
You may click “Customize” to define the metrics you wish to compare the journals with.
