The h-index has been a major tool for the assessment of university research over the last few years. The index is included in Google Scholar profiles and has been used as an indicator in the QS World University Subject Rankings. Although it Is ubiquitous in research evaluation many observers and scientists have expressed strong opposition claiming that it is crude and takes little account of differences in disciplinary citation and publication practices.

The h-index is a metric that captures both quality and quantity of publication. It is the number of papers that have been cited as frequently as or more than the number of papers analysed. Thus, an author of five papers each of which has been published five times or more would have an h-index of 5.

The h-index was invented by Jorge Hirsch, a physicist at the University of San Diego and was originally intended only to evaluate and compare research in theoretical physics.

Hirsch himself has now criticised the metric in a paper on superconductivity in Physics and Society Newsletter which has been reported in Nature Index by Gemma Conroy. He noted that while it was one of the best measures of scientific research it can have unintended negative consequences. It might encourage researchers to pursue hot topics in fashionable fields and cover up difficulties with unsound theoretical approaches.

Sources:

• Nature Index
• Physics and Society Newsletter