A researcher’s (or scholar’s) productivity and impact in the publication are measured by his or her h-index. For instance, if a researcher’s h-index is 10, it means that the researcher has at least 10 publications and 10 of which had been cited at least 10 times. If, on the other hand, a researcher has published 10 papers but each paper has received 1 citation, the h-index would be 1. How do we determine the h-index of a researcher? The first step is to list all the papers according to the number of citations in descending order (i.e. from the highest to the lowest citations). The h-index is at the point where the xth paper on the list equals x citations (or more) and total citations for the next paper (let’s say y) is less than y. Let us look at 2 examples below:

Researcher A: Paper 1: 10 citations; Paper 2: 3 citations; and Paper 3: 2 citations. In this case, Researcher A’s h-index is 2 because his or her next paper (i.e. Paper 3), has received only 2 citations (i.e. less than 3). His or her h-index will rise to 3 when the 3rd paper has received at least 3 citations.

Researcher B: Paper 1: 100 citations; Paper 2: 20 citations; Paper 3: 10 citations; Paper 4: 5 citations; and Paper 5: 3 citations. In this case, the h-index for Researcher B is 4 because the total citations for the 5th paper are only 4 (i.e. less than 5). His or her h-index will rise to 5 when his or her 5th paper has been cited at least 5 times from currently 3 times.