“Why do zebras have stripes?”
“Why did T. rex have such small arms?”
In evolutionary biology, functional questions like those are notoriously tricky to answer, because people tend to mix up two separate questions: the origin of the feature, and the current use of the feature.
People often have difficulty grasping that those two things are different. This leads to questions like, “What good is half a wing?” . The implication is that that because wings are used for flying now, they must always have been used for flying, so how could they evolve?
The answer is that the bits that make up a wing can be used for lots of things, and that you can have a functional shift. Something that’s great for insulation or display like feathers proves incidentally useful for gliding. The incidental use eventually becomes the primary use.
But Garfield’s own account of the history of the Impact Factor shows this is not true (link to edited version; full version can be found in external links).
Garfield was involved in creating the Genetics Citation Index in the 1950s, and needed to decided what journal to include in the index. They first tried just counting citations to journals, which favoured journals that just published a lot of papers. They realized that “total citations” missed journals that published fewer papers that were highly cited.
Impact Factor helped solve this problem. It wasn’t about libraries at all. So where did the “Impact Factor was created for libraries” belief come from?
In the 1960s, the Genetics Citation Index broadened out to become the Science Citation Index. Garfield did lots of research on citation patterns, and published a 1972 paper in Science about citation analysis. Garfield talks about all the findings using this measure, Impact Factor, that he created more than a decade earlier.
But at the end of the paper, there’s a section that begins, “Some applications,” and the first sentence is:
The results of this type of citation analysis would appear to be of great potential value in the management of library journal collections.
And that’s the origin of the myth that Impact Factor was created for libraries.
That 1972 Science paper went on to become the one that many people referred to in discussions of Impact Factor. And it’s easy to see how Garfield’s suggestion that libraries could use Impact Factor to make purchasing decisions could morph into, “Garfield created Impact Factor for libraries.” Because people don’t always read the original papers of the things they cite in details.
The Impact Factor not only shows how easily origin gets muddled, it also shows the concept of functional shift. Because libraries did use it for purchasing decisions, and then administrators started using it to make hiring, tenure, and promotion decisions. DORA is trying to provide a new selection pressure that could cause another functional shift, away from evaluating researchers.
External links
Essays about Impact Factor by Eugene Garfield
Garfield E. 1972. Citation analysis as a tool in journal evaluation. Science 178: 471-479. https://doi.org/10.1126/science.178.4060.471
