Impact factor

A graduate or undergraduate student hoping to publish research may ask a librarian at the Thammasat University Libraries:

What does a journal’s impact factor mean?

Impact factor (IF) or journal impact factor (JIF) states the average annual number of citations to recent articles published in an academic journal. It is an attempt to show the relative importance of a journal in its field. If an article is cited often, that would suggest that a journal has many readers who use the information they learn in it for their own future research. Since 1975, impact factors have been calculated every year for journals listed in the Journal Citation Reports. This is one indicator which may be useful, because there are so many journals that it might otherwise be difficult to know quickly if a journal is important, without knowing an impact factor. There are estimated to be over 11,000 science and social science journals in the world, and no one can know them all, not even specialists in these fields. When students and ajarns are advised to try to publish in journals with significant impact factors, there can be some problems.

First, sometimes authors of articles are evaluated based on the impact factor of the journals they publish in. This can create trouble, since any journal, even influential ones, publishes articles of different quality. Also, some companies offer misleading data about impact factors, calling them Global Impact Factor (GIF), Citefactor, or Universal Impact Factor (UIF). These may be safely ignored. The student may ask:

So how do I find the real impact factor of a journal?

One sure way is to look at a reliable website such as the University of Illinois Library. Try to avoid commercial websites that look like they are selling something. Anyone who reads about impact factor soon discovers that there are many ongoing issues with this information when used to judge the value of research. Some critics argue that impact factors are not always reliable or may not be enough if considered as the only information about a journal. Some editors of journals manipulate data to make their publications seem more influential than they really are. For example, some editors publish more reviews in a journal than articles, because reviews tend to be read and cited more than articles. This is in part because they are shorter and easier to read. Some editors only publish articles by very well-known, established experts in their field, which are guaranteed a high impact factor because many readers will want to see what these famous authorities have written. For these journals, it is a waste of time for students to try to offer their research, since the editors do not consider work by relatively unknown researchers. We may advise the student:

Ask your ajarn for the names of the most important publications in your field of study that all ajarns read.

If the student asks:

How else can I see if a journal is influential, in addition to knowing its impact factor?

Our replies would be:

• Look in your faculty library or at the Pridi Banomyong Library, Tha Prachan Campus or Puey Ungphakorn Library, Rangsit Campus.
• Quickly browse through some sample journals in your field of study. You can also find them online by using the TU Libraries databases.
• See if the journal looks like a serious professional publication.
• Does it have any articles that interest you and seem to relate to your research? Then it may be worth writing to the editor of the journal to see about publication.

In evaluating a journal, it can help to see the bound and printed version of the journal, since online articles generally all look alike. If a journal is professionally presented, printed, and produced, this is easily visible when students hold the journal in their hands. The journals which the TU Libraries subscribe to are those which ajarns tell us are the most essential for research and learning.

(All images courtesy of Wikimedia Commons)