While conducting scholarly research you’ve probably seen mentions of ‘impact factors’. We’ll use today’s post to provide a little more information and to link you out to some great resources to learn more.
Generally speaking, impact factors are measures (using varying metrics but often citation counts) that suggest the ‘importance’ or ‘significance’ of either an author, article, or journal. Various stakeholders like to use these impact factors as proof that either their work or their journal or their institution, etc. is valuable to the research community.
There are many types of impact factors and each is calculated differently. There are measures for authors which use formulas based on how many articles they’ve published and how many times each of those articles have been cited. There are other measures for journals which might look at how often a typical article in that publication is cited each year, and so on.
A couple common author-level impact measures include:
- H-Index: An author-level metric used to calculate an individual scholar’s research impact. Check out this guide from Boston College to learn more.
- Altmetric: As described on the Altmetric website, “Altmetrics are metrics and qualitative data that are complementary to traditional, citation-based metrics. They can include (but are not limited to) peer reviews on Faculty of 1000, citations on Wikipedia and in public policy documents, discussions on research blogs, mainstream media coverage, bookmarks on reference managers like Mendeley, and mentions on social networks such as Twitter.” Check out our blog post about Altmetrics for more info.
What gets a little complex, of course, is whether these formulas/calculations are accurate measures of something like ‘impact’. Some of the formulas will include self-citations which can skew results. Others have argued that citation counts do not reflect the full ‘impact’ of a work. There is a recent movement in ‘altmetrics’ to track impact in other spaces such as social media, as mentioned above, to give a more complete picture of how a work is being used and discussed.
Some tools, like Google Scholar’s author profiles, will include a list of author-level citation metrics. You can view this data on an author’s profile page and if you hover over the name of the metric you can reveal a definition of how it was calculated:
There can be a TON to know about impact factors and citation metrics and some of it can get quite complicated. UC Irvine has a wonderful LibGuide which provides a lot of this information is easily digestible chunks: http://guides.lib.uci.edu/c.php?g=334451&p=2249950.
The University of Illinois also has a great guide which covers journal impact factor in particular: http://researchguides.uic.edu/if/impact. Lastly, Elsevier has put together a nice list of various impact measures and their formulas: https://www.elsevier.com/authors/journal-authors/measuring-a-journals-impact.
Next time you see a journal advertising its impact factor, or you’re trying to understand the influence of a scholar’s research in their field, consider drawing on some of these tools to gain better insight into what those impact factors and influences might mean.