Suitability of h- and x-indices for evaluating authors' individual research achievements in a given short period of years: A bibliometric analysis.

We verified that the h-index failed to differentiate authors' IRAs among author groups in a short time period. The x-index combined with the Kano map is recommended in research for a better understanding of the authors' IRAs in other journals or disciplines, not just limited to the journal of PloS One as we did in this study.