The Journal Impact Factor (JIF) is an average of the number of citations received by a journal in a given year. For example, the Journal Impact Factor for a journal in 2015 is calculated by taking the number of citations made in 2015 to the articles published in the journal in 2013 and 2014 and then divided by the total number of articles published in that journal in 2013 and 2014.
The Journal Citation Reports (JCR) are in 2 parts on Web of Science. One is for Sciences from the Science Citation Index and one for Social Sciences from the Social Sciences Citation Index.
Today the JCR is widely used to identify the top journals in a field. These are rated based on citation behaviour. The journals are ranked in JCR using the well-known and accepted journal measure. The Journal Impact Factor is often used by individual researchers to identify the best titles in which to publish and gain recognition and potential impact. Citation varies considerably between disciplines and therefore disciplines cannot be compared.
Only references in articles published in journals indexed by Web of Science are included in the JCR.
Scopus uses its own version of impact factors called the Source Normalized Impact per Paper (SNIP)."You can use the Journal Analyzer to compare up to 10 Scopus sources on a variety of parameters: SJR, SNIP, citations, documents, and percentage of documents not cited. The analyzer is available in both a Line Chart and a Table view. The Line Chart displays information in a line graph, with separate graphs for each parameter. The Table lists parameters together in one table."
There are different ways to measure journal impact. Here are a few more places you can look to locate data on scholarly research:
CiteScore is a set of journal metrics produced by Elsevier and calculated using citation data from Scopus. A journal's CiteScore represents the average number of citations received in the CiteScore year (e.g. 2015), by papers published in the three preceding years (e.g. 2012, 2013 and 2014). In contrast, the Journal Impact Factor (Clarivate Analytics) uses a two year, rather than three year, window. All types of documents (research articles, review articles, conference proceedings, editorials errata, letters, notes, and short surveys) are included in the CiteScore calculation. Although articles in press are included in Scopus they are not included in the calculation. CiteScore rankings and CiteScore percentile metrics are also available.
CiteScore metrics (along with the SJR and SNIP) can be viewed on Scopus or through Elsevier's Journal Metrics website.
Example of CiteScore metrics
Google Scholar Metrics give an indication of the visibility and influence of recent articles in scholarly publications. Google Scholar Metrics summarise recent citations to many publications, to help authors as they consider where to publish their new research.
You can browse the Google Scholar top 100 publications in several languages, ordered by their five-year h-index and h-median metrics. To see which articles in a publication were cited the most and who cited them, click on its h-index number to view the articles as well as the citations underlying the metrics. You can also explore publications in research areas of your interest. To browse publications in a broad area of research, select one of the areas in the left column. For example: Engineering & Computer Science or Health & Medical Sciences.
To explore specific research areas, select one of the broad areas, click on the "Subcategories" link and then select one of the options. For example: Databases & Information Systems or Development Economics.
Browsing by research area is, as yet, available only for English publications. You can search for specific publications in all languages by words in their titles. Scholar Metrics are currently based on our index as it was in June 2018.