Author Impact Factor: A Framework for Evaluating Authorship and Scientific Contribution

In the decade since Hirsch defined h, there has been widespread acceptance of the h-index as a bibliometric indicator. Although the h-index has been validated in numerous applications and settings, the bibliometric has some important limitations. Most importantly, the h-index does not account for authors' individual contributions to manuscripts within their h-defining body of work. Since each author makes a variable contribution to a piece of scientific work, an author-adjusted index would more fairly reflect scholarly productivity. We propose the author impact factor (AIF), which accounts for authorship position and number of co-authors, to adjust the h-index and more fairly account for contributions to the body of scientific work. The AIF is calculated from the h-index and an author's proportional contribution (α) to each h-defining manuscript. The α is based on authorship position and the number of co-authors. Using the golden ratio (φ), the calculation of α for each h-index defining manuscript is simple and axiomatic. To demonstrate the utility of this index, we calculated the AIF for a sample of high-impact scientists. The results show that the AIF maintains all the benefits of the h-index while adjusting the bibliometric for author-specific factors. Therefore, AIF more accurately reflects total "research output" and can be used to better compare authors' scientific contributions.