Thursday, 13 September 2007


Universities are continually looking for ways to quantify the research output of their academic staff. With databases such as 'Web of Science' on the Thompson Scientific ISI Web of Knowledge website, it is possible to obtain various statistics related to the number of publications for a given researcher. The factors that universities are looking for are how many articles one publishes, but also how often they are cited as a reference in another publication. The most mind-boggling statistic obtained from this analysis is the h-index. If an author's publications are ranked according to the number of citations with the most cited article listed first, the h-index is the number where the h-th article has been cited either h or more times. Huh? In other words, an h-index of 10 means that there are 10 publications that have 10 or more citations. The 'Web of Science' argues that "This metric is useful because it discounts the disproportionate weight of highly cited papers or papers that have not yet been cited." While this may be the case, it seems that it does not necessarily give an indication of the impact of the specific research or article. For example, an article that has been cited 1000 times has presumably had more of an impact on the scientific community than an article that has only been sited 100 times. So what does the h-index actually mean? Someone who has 50 articles each of which has been cited 50 times (h-index: 50) would appear to be more productive than another person who only has 5 articles that have been cited 500 times (h-index: 5), but does that mean that the first person is a better scientist? By the way, my h-index is 6.

1 comment:

contrarybear said...

My h-index might be as high as 2, but I suspect it's only 1.