The h-index is computed from a citation list by sorting papers by citation count in descending order and finding the largest h where the h-th paper has at least h citations. It conflates productivity and impact in a single integer. The metric is field-dependent (citation cultures and densities differ widely), time-dependent (it can only grow), database-dependent (Google Scholar, Scopus and Web of Science return different values), and insensitive to highly cited outliers above the threshold. Responsible-assessment frameworks (DORA, Leiden Manifesto, CoARA, Hong Kong Principles) explicitly caution against using h-index for hiring, promotion or funding decisions.
References
- Hirsch JE, PNAS 102(46):16569-16572, 2005. Bornmann L & Daniel HD 'The state of h index research', 2009.