How to Measure Researcher Impact

Researcher Impact

Research impact is often measured using quantitative methods such as citation counts, the h-index, and journal impact factors. It can also be described qualitatively. Currently, there is no one tool or system that completely measures impact. Each database or tool uses its own measurement systems, indices, data and authority files. And it is difficult to use these tools to compare across disciplines that have different research and publication practices. Furthermore, as scholarly communication continues to evolve, the limitations of existing metrics and tools are becoming increasingly evident. 

There is no one number to perfectly or “correctly” represent the research impact of an individual or a group of researchers.

An author's impact on their field or discipline has traditionally been measured using the number of times they have published and the number of times their academic publications are cited by other researchers. Although the simplest way to demonstrate your impact is to create a list of your publications and the number of times they have been cited, numerous algorithms based on publication data have also been created. Below are some of the more common metrics and tools you can use to measure research impact.

Common Measures of Author Impact

h-index

  • Attempts to measure: quality and quantity of author's work
  • h-index is the number of papers (h) that have received (h) or more citations. An author with an h-index of 8 has 8 papers cited at least 8 times.
  • Strengths:
    • Includes more than a single data point (e.g. quality and quantity)
    • Easy to calculate and understand
  • Limitations:
    • Inaccurate measure of early career researcher impact
    • Only measures published works
    • If a specific resource is used, such as Web of Science or Scopus, results are limited to what the tool has indexed

g-index

  • Quality and quantity of author's work, with more weight on quality
  • To calculate the g-index an author’s articles are ranked in decreasing order of the number of the citations each received. The unique largest number such that the top g articles received, together, at least g^2 citations is the g-index.
  • Strengths:
    • Looks at overall record
    • Allows highly-cited papers to bolster low-cited papers
  • Limitations:
    • Only measures published works
    • Complicated calculation
    • Not as widely known or accepted as the h-index

i10-index

  • Quality of author's work
  • Counts the number of publications with at least 10 citations
  • Strengths:
    • Easy to calculate and understand
    • Google Scholar’s My Citation feature is free and easy to use
  • Limitations:
    • Used only in Google Scholar
    • Limited to works indexed by Google Scholar
    • Only measures published works

 

Group or Departmental Impact

A research group or department may wish to gauge the impact of its research or learn how it compares to its peers. Similar to individual impact measures, these numbers can give only a partial story of impact.

Publication Activity and Citation Count

Simple indicators of activity and impact for a group or department can be discovered by searching all the individuals in the group and combining their names with the OR search operator. These raw counts will vary depending on what the data source includes. The h-index for a group takes all the publications of every member of the group and creates a cumulative score. Below are some common tools used to obtain publication and citation data.

Citation database that allows you to create a Citation Report and calculate an h-index.

A software program that must be downloaded and installed on a computer. It allows researchers to provide evidence of their research impact. Citations are obtained from Google Scholar. Besides basic statistics it calculates H-index, G-index, and E-index, among others.

A browser extension that queries Google Scholar. Network visualizations are based on crowdsourced discipline annotations of the queried authors.

Both can be used to obtain citation counts for articles. Google Scholar Citations also allows authors to keep track of citations to their articles.

For more information or assistance, email the Library Impact Metrics team