H-index

A scholar with an h-index of 20 has 20 papers cited at least 20 times each. The measure rewards a sustained body of moderately cited work over both one-hit wonders and prolific authors whose papers go uncited. It is easy to compute from databases such as Scopus, Web of Science, and Google Scholar, though each yields a different value because they index different sources.

The metric has structural blind spots. It never decreases, so it climbs with career length and cannot compare a graduate student to a senior professor fairly. It ignores author position and contribution, varies enormously between fields with different citation cultures, and can be inflated by self-citation. Variants like the g-index and m-quotient try to patch specific weaknesses.

As with journal impact factor, the h-index is a crude summary that should never substitute for reading the work. It belongs to the same family of citation metrics whose misuse DORA and the Leiden Manifesto push back against.