H-Index

The h-index, or Hirsch index, is a quantitative metric proposed by physicist Jorge Hirsch in 2005 to measure researcher productivity and citation impact simultaneously. A researcher has an h-index of h if they have published at least h papers, each cited at least h times. For example, an h-index of 20 means the researcher has 20 papers each cited at least 20 times. The h-index is widely used in research evaluation, hiring, and promotion decisions, though experts debate its limitations. It provides a single number balancing quantity of publications against quality of citations, offering an intuitive summary of research career impact.