The relevance of publication journals can vary widely across research disciplines. Even within a discipline, not all journals are consistently relevant to all researchers. This is where journal-related indicators come in. These should help to answer the following questions individually:
In which journal should I publish?
Which journal is particularly relevant in my discipline?
Journal Impact Factor (JIF)
The Journal Impact Factor (JIF), often just called the Impact Factor (IF), is calculated by dividing the total number of citations in a journal from two years by the number of articles published in the journal in those two years. If a journal published a total of 100 articles in 2020 and 2021 that were cited a total of 200 times, the journal's JIF in the reference period is 2. A JIF can only ever be calculated for completed volumes. This means that the JIF of a journal given in 2022 is calculated from the two previous volumes.
The JIF is often mistakenly equated with the research performance of the publishing authors, although it is a mere journal indicator. Moreover, a publication in a journal with a high JIF is not indicative of the scientific quality of the publication itself. This was also never the purpose of the JIF, which was originally developed by Eugene Garfield at the Institute for Scientific Information with the aim of helping libraries select journals to subscribe to given limited resources. First calculated for a selection of journals in 1975 and published as part of the Journal Citation Reports (JCR), both the JIF and the JCR are now a product of the Clarivate Analytics company.
Source Normalized Impact per Paper (SNIP)
SNIP relates the average number of citations a journal receives to the average number of citations in its respective discipline (the citation potential). A SNIP of 1 means that a journal is cited according to the average of the corresponding research field. A SNIP of 2 means that articles in the journal are cited twice as often on average. The goal of the SNIP is to make the coverage of publications within different disciplines comparable. The SNIP is issued by Elsevier via their database Scopus (see below).