What Is a Good Impact Factor of a Journal?
What is a good impact factor of a journal? Well, it is not a question that can be given a simple numerical answer that will apply to all journals. In this post I explain why this is the case. I also explain what the Journal Impact Factor or JIF calculated by Journal Citation Reports (JCR) is and I describe how to learn about and compare the impact factors of journals in particular disciplines. Considering journals & their impact factors in relation to other journals assigned to the same JCR subject categories is the key to making good use of citation counts & the impact factors based on them.
The impact factors published by Clarivate Analytics on the JCR website are calculated from accurate and authoritative measures of the citations earned by a wide range of scholarly journals, especially those in the sciences and social sciences. For the annual JIF, JCR captures all the citations made during a single year to the articles published by a journal in the two preceding years. The calculation for the 2018 JIF of a particular journal therefore requires counting all citations that refer to the journal’s 2016 and 2017 articles. The total is then divided by the number of citable items published by the journal in those two years to arrive at the current year (2018) JIF, which is released in 2019. For example, if a journal publishes 100 articles in 2016 and 2017 and those articles receive 400 citations in 2018, the 2018 JIF for the journal would be 4. This indicates that the articles published by the journal received, on average, four citations each, but in reality citations are unevenly distributed and review articles usually earn far more than research articles do.
What Is a Good Impact Factor of a Journal Indexed in Journal Citation Reports?
So, is 4 a good impact factor for a scholarly journal? The answer will vary depending on the discipline and specialisation of the journal. In many cases a JIF of 4 could be very good indeed, and some journal proofreaders aim for that number, but for certain journals it might be no more than acceptable or ordinary, whereas for others it would be considered exceptional. There can be no doubt that a journal with a JIF near 250 receives an extremely large number of citations and boasts an exceptionally high JIF, even for the sciences where citations tend to be more immediate and frequent than in the humanities. When the top science journal earned that score, the next journal on the list had a much lower though still impressive JIF of almost 80, while the journals just below it were sitting in the 50 range. In other areas, a JIF as high as 50 has never been achieved and likely never will be simply because citation practices and patterns will not allow it. In most fields of study a JIF of 10 or greater is excellent and in many anything over a JIF of 3 is considered good, but it is essential to remember that JCR impact factors for journals vary markedly across disciplines.
For this reason, the impact factors of journals cannot be compared in meaningful ways across disciplines, but a journal can be productively compared with other journals in the same JCR subject category to determine what a good impact factor for a journal in the category may be. To do so you will need to access the JCR website on the InCites platform and choose Browse by Category on the landing page. This will take you to a page where the JCR subject categories appear in a list ranked by the number of journals in each category, but the order can be rearranged by clicking on the column heading, and particular categories can be selected by using the menu to the left. Clicking on the name of a specific category in the list opens the profile page offering an overview of that category, and clicking on the number of journals for a particular category takes you to a list of all the journals included in that category. This journal list is ranked according to the JIF, so the question of what is a good impact factor of a journal in the category is easy to answer. Comparing all the journals in a subject category via the JIF is straightforward as well, and you can also select particular journals for comparison and refine your selection in a variety of other ways by choosing from the options available in the menu to the left.
