The Hirsch index, or h-index is a widely used citation statistic that, arguably, accurately reflects the impact of a scientist. It takes into account the number of publications as well as how often those papers are cited. For example, an author with 4 publications each with at least 4 citations, has a h-index of 4. Another author with 200 publications, each cited only once, has a Hirsch index of just 1, simply because the papers are not cited more than once. A possible confounding factor in this index are self-citations. If the latter fictional author would have cited all his previous work in his latter 100 papers, their h-index would sky rocket to 100.
Google Scholar nicely provides the h-index and at my institution they use Google Scholar to calculate the h-index for every researcher. However, Google Scholar includes self-citations, while I have heard colleagues from other institutions say that a h-index should not include self-citations, for reasons illustrated above.
My question is: should the h-index include or exclude self-citations? Is there a consensus reached on this topic? If there is no consensus, should the h-index then not be accompanied by an identifier to clarify which of the two methods was adopted to calculate it?
- Shema, Sci Am blogs, 2012