Ask Ediqo: What is the h-index and how is it calculated?
The h-index was proposed by physicist Jorge E. Hirsch in a paper published in the Proceedings of the National Academy of Sciences (PNAS) in 2005.
h is the minimum number of papers from an author that received at least h citations. As such, it is as a measure that characterizes both the output and the scientific impact of a scientist’s body of work.
Let’s say an author published 10 papers in his career (papers ordered by times cited):
- Paper 1: 0 citations
- Paper 2: 2 citations
- Paper 3: 5 citations
- Paper 4: 5 citations
- Paper 5: 5 citations
- Paper 6: 5 citations
- Paper 7: 10 citations
- Paper 8: 15 citations
- Paper 9: 25 citations
- Paper 10: 55 citations
In this example, the h-index is 5. The author has at least 5 papers (Papers 6–10) that received at least 5 citations. It is not 6, as he only has 4 papers with 6 or more citations.