Measuring Research Impact

This guide provides an introduction to measure the impact of publications and authors for promotion and tenure and other purposes.

Measuring Author Impact

Author metrics attempt to quantify the productivity or influence of a particular author. They are often calculated using (sometimes weighted) algorithms that measure the number of citations to a particular author's work. 

H-Index

The most widely used metric, h-index, identifies the highest number of an author's papers to have the same or higher number of citations.  For instance, for an author to have an h-index of 7, he or she must have at least 7 publications with 7 or more citations.

Advantages

  • Direct comparisons can be made within disciplines
  • Single value used to measure quantity and impact

Disadvantages

  • Inaccurate for early-career researchers
  • Only articles indexed in Web of Science are used in calculations
    • If a researcher publishes in a journal not indexed by Web of Science, the article and any citations to it will be excluded from the calculation
  • Does not account for articles that are very poorly or very highly cited works

Tools for Finding h-index

Utilize the following databases to look up your h-index. Keep in mind that each resource will only count the number of citations within their database in their calculations. Therefore, your h-index number will be different in each database.

The following image is an example of the h-index of the same researcher from Google Scholar, Web of Science, and Scopus. Notice that the calculated h-index is different in each database.

screenshots from google scholar, web of science, and scopus demonstrating the different h indexes in each database for the same author

i10-Index

Created by Google Scholar and used in Google's My Citations feature, the i10-index indicates the number of publications by an author that have been cited at least 10 times by others.

Advantages

  • Simple and straightforward to calculate
  • My Citations in Google Scholar is free and easy to use

Disadvantages

  • Only used in Google Scholar

G-index info

G-Index is calculated as the largest number n of highly cited articles for which the average number of citations is at least n.  G-index adds more weight to highly cited publications and is considered by some to be more effective than h-index.

Advantages

  • Takes into account highly cited works
  • Makes more apparent the difference between authors' respective impacts. 
    • Inflated values help to give credit to lowly-cited or non-cited papers while still giving credit for highly-cited papers

Disadvantages

  • May not be as widely accepted as h-index