Quantifying Scientific Merit: Is it Time to Transform the Impact Factor?

> Thus ornament is but the guiled shore To a most dangerous sea; the beauteous scarf Veiling an Indian beauty; in a word, The seeming truth which cunning times put on To entrap the wisest. > > —William Shakespeare, Merchant of Venice, Act III, Scene 2 1596–97 Use of impact factor (IF) to quantify scientific merit is severely flawed. Three changes are recommended to strengthen the assessment of journals that primarily report basic research: (1) calculate IF based on original scientific contributions; (2) use the 5-year IF; and (3) eliminate self-citation. For journals reporting clinical trials and population research, an index of readership, such as downloads, would better reflect true influence. For journals that report both basic and clinical research, a hybrid measure would assess both research quality and influence. The time has come for the scientific community to transform IF. Quantification is the bedrock of science. Yet, when it comes to mathematically estimating the relative merit of scientific articles and the journals in which they are published, the scientific community has struggled with significant challenges. Surprisingly, despite over a half-century of study and application of quantitative methods to rate scientific impact, consensus has still not been achieved on the best way to measure the true quality and influence of a scientific contribution or a journal. This conundrum is not because of a lack of available measurement tools, for many have been developed. Rather, it is the reluctant acceptance by the science and publishing world of one of them, IF, as the appropriate gauge of scientific quality. IF, a citation-based tool, was developed in 1955 by Eugene Garfield and has been released annually since 1975 for those journals indexed in Journal Citation Reports .1,2 IF is defined as the mean number of citations received per article published in a specific …