I have previously blogged about the Milena Penkowa case that has entertained the Danish research community in the first half of 2011. If you want an English update there is an overview in the April article Penkowa for dummies.One of the latest to jump on the wagon for Penkowa bashing is geologist Peter Riisager. Back in March he looked on the self-citations of Penkowa and reported it on his blog. He found that 54% of Penkowa’s citations where her own. The story was picked up a couple of weeks ago by the university newspaper Danish and English as well as a Danish science web-site. When Riisager finding that Penkowa has over 50% self-citations he links to a Nature blogger that claims that “Bad guys have > 50% self-citations” and “good guys have self-citations as < 50% of total cites (I [Brian Derby] am at 25%)”. qed: Penkowa is a bad guy. But is Riisager (and blogger Brian Derby) right? I cannot find out which method he used. 50% self-citations sounds fairly much. How can we investigate this further? Well, here is my methodology: I use ISI Web of Science, search on an author, press “Create Citation Report” to get number of articles the author has written (“Results found”) and the number of citations (“Sum of the Times Cited”), For the number of non-self citations I press “View without self-citations” and read off “Result: ” in the upper left corner of the web-page. Is that an ok procedure? Nah. I think the problem is that “Sum of the Times Cited” refers to the number of citations while “View without self-citations” refers to the number of papers with citations without self-citations. What we should (also) do is to get the number of papers with citations (“View Citing Articles”). The problem is that there are multiple citations in each paper. What we also would like to have is the number of citations without self-citations, but I don’t know how to get that number from ISI Web of Science. Below I have attempted a count on Milena Penkowa, Peter Riisager, myself and big shot neuroimaging analyzer Karl J. Friston. The “self-citation rate (A)” is computed what I believe is the wrong way (citations-Papers with non-self citations)/citations, while “self-citation rate (B)” is computed by the number of citing papers (Papers with citations – Papers with non-self citations)/Papers with citations.
|Author||Papers||Citations||Papers with citations||Papers with non-self citations||Self-citation rate (A)||Self-citation rate (B)|
(2012-03-07: language correction)