Research Impact

An author's research impact on their field or discipline is measured using their publication counts and citation counts. The calculation will depend on the tool used. No one metric can capture all citations or "impact," and early career researchers are disadvantaged.

The h-index is defined as "the number of papers with citation number ≥ h , as a useful index to characterize the scientific output of a researcher" (J.E. Hirsch, 2005). For example, an h-index of 28 means there are 28 publications that have 28 citation or more for each. The h-index measures the impact of a researcher or group of researchers rather than a journal.

Tools for measuring the h-index:

• Web of Science: library subscribed database
• Scopus: library subscribed database
• Google Scholar: free search engine 

Limitations of the h-index:

• Inconsistent values between Web of Science, Scopus, and Google Scholar due to different coverage among these resources.
• Does not fairly evaluate the research impact of early career researchers.
• No data available for researchers in some disciplines, e.g. Arts and Humanities. 
• Cannot capture full impact of an author or a group of authors, as not all publications are indexed in the available tools.

What is the h-index and what are its limitations? Or: Stop using the h-index (Educational video produced by the ScholCommLab).

This metric is created by Google Scholar and can only be found when an author has created a public profile. The i10-index is the number of publications with at least 10 citations.

Limitations:

• Used only in Google Scholar
• Not used as widely as the h-index