Methods to Evaluate an Author

Traditionally, the sole method to measure the performance of a researcher/author is based on the number of publications. More publication means better performance. In fact, most universities require their researchers and academic staff to publish a minimum number of publications every year. i.e 4 international journal papers a year. However, this method of assessment may lead to a situation called the ‘salami publishing’. This kind of situation happened when an author tend to publish materials which suppose to be reported in one paper to several papers simply to increase the number of publications. As a result, the published papers will be full of old materials and just a minute percent of new knowledge.

Then, people start to consider the total/average citations per paper. The number of citations indicates the number of people who refer to a paper and eventually its quality. But, question arose. Which one is a better author; the one who produce one paper with 200 citations and zero for others (one-hit wonders) or an author who publish several papers but each paper has 20 citations? Besides, total/average number of citations per paper may penalize productivity.

Later, journals were evaluated periodically and given the impact factor. Generally speaking, only high quality research papers can be published in high impact factor journals. The higher the impact factor, the harder to publish in it. So, where authors publish their papers is also used to evaluate them. However, impact factor which can vary from less than one to above one hundred also vary depending on research areas. A science journal may have impact factor of 100 while journal for social sciences have impact factor of 0.1. So, it seemed unfair to compare authors from different background by using impact factor.

In 2005, a new method of evaluating authors called ‘h-index’ was proposed by Jorge Hirsh, a condensed-matter physicist and peace activist at University of California in San Diego. h-index combines quantity, quality, productivity and influence to evaluate authors. It is easy to determine and dynamic which means it can change as citations and publications increase. Besides, it ignores the highly and poorly cited papers (one-hit wonders) and age of author is also not taken into account. This means both junior and senior authors can have high or low h-index. Based on this method, a researcher has index h if h of his papers have at least h citations each and the other papers have no more than h citations each.

Besides, h-index also can be used to measure the performance of institutions, universities, departments, faculties, journals etc. The h-index method is not perfect but so far, it is the most balance method of evaluation.

I have used SCOPUS to look at the performance of Prof. Joe C Campbell, who is generally accepted as the guru or world leader in the field of avalanche photodiodes research. Click on the pictures to enlarge.

Prof. Campbell has published 453 papers, his papers were cited by 2688 people and has h-index of 29 (very large h-index)

The highest number of papers were published in 2002; 37 papers

Distribution of citations

Don't be shocked if you find out that a professor in small/new university has zero h-index and 2 or 3 citations only. Publications produced by a professor in top university in a year also may be more than the number of publications produced by a small UNIVERSITY.

Curious to see how your supervisor perform?