Researcher Impact

There are a few ways to measure an author's impact:

• Document Counts - the number of publications an author has authored
• Citation Counts - the number of times an author’s publications are being cited by other researchers
• h-index - an index to measure both the productivity and impact of the published work of an author/a researcher
• i10-index - the number of publications with at least 10 citations

Document Counts, Citation Counts and h-index are available in Web of Science, Scopus and Google Scholar while i10-index is only available in Google Scholar.

h-index or Hirsch index was proposed in 2005 by Jorge E. Hirsch to quantify the research achievement of physicists based on their publication record. The number attempts to measure both the productivity and citation impact of the publications of a scientist or scholar.

The diagram shows a researcher with an index of h. Out of all his publications, h publications have at least h citations each. For example, an h-index of 20 means that, out of all papers published by an author, 20 of them have been cited at least 20 times. 

Reference: https://en.wikipedia.org/wiki/H-index

Please note the followings when using h-index:

• Different databases have different content coverage and this will have an impact on the results, for example, the h-index of an author may be different in Scopus, Web of Science and Google Scholar.
• The value of h-index from Google Scholar may be higher than Scopus and Web of Science because Google Scholar has larger content coverage and looser inclusion criteria.
• Citation practices vary across disciplines; it is not advisable to compare the h-index of scholars in different disciplines.
• The h-index may vary depending on how long the scholar has been publishing and on the number of articles they’ve published. Older scholars will tend to have a higher h-index than younger scholars based on the fact that the former group have more publications. 
• If you find it difficult to locate all your publications in Web of Science, creating a ResearcherID profile and adding all your publications from Web of Science will help you accurately track your citation counts and h-index.