How to calculate impact factor?
The impact factor of a journal is calculated by dividing the amount of current year citations to the source items published therein journal during the previous two years. it’s denoted as a ratio between citations and up to date citable items published.
Thus, the Impact Factor of 6.125 for the journal, Academy of Management Review for 2008 indicates that on the average, the articles published during this journal within the past two years are cited about 6.125 times.
Factors to think about While Consulting Impact Factors
- Publication Date:
The impact factor is predicated on citation frequency of articles from a journal in their first few years of publication. This doesn’t serve the journals with articles that get cited over a extended period of your time (let’s say, 10 years) instead of immediately. In other words, journals in rapidly expanding fields like cell biology and computing tend to possess much higher immediate citation rates resulting in higher IFs than journals in fields like Education or Economics.
- Journal Impact Factor not Article Impact Factor:
Citations to articles during a journal aren’t evenly distributed. In fact, some articles during a journal might not be cited in the least but a couple of highly cited articles could lead on to a high IF. Therefore, the IF doesn’t accurately reflect the standard of individual articles published during a journal. Also, journals with more issues and articles can have higher Impact Factors which might be misleading because it doesn’t really reflect the standard of articles.
- Review Articles:
Review articles (which tend to receive more citations), editorials, letters, and news items aren’t counted in article total but if cited are counted as citations for the journal. This leaves room for manipulation of ratio want to calculate impact factors resulting in inflated impact factors in some cases.
- Clinical Journals:
Clinical journals usually have low citation counts. This puts such journals at an obstacle with research journals within the field that have higher citation counts.
- Uneven Coverage:
The Journal Citation Reports focuses far more on disciplines where the first means of publishing is thru journal article. It provides less coverage to areas in Social Sciences and Humanities, where books and other publishing formats are more prevalent.