Measuring Research Impact: Author Metrics

An author's impact on their field has traditionally been measured using citation counts, i.e. the number of academic publications he or she has authored and the number of times these publications are cited by other researchers.  Thus, a simple way to demonstrate your impact is to create a comprehensive list of your publications and the number of times they have been cited.

Different indices have been created that calculate an author impact 'score' using data on their publications

h-Index (the most widely used)

The 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.

Most researchers obtain their h-index from Web of Science, Scopus, or Google Scholar.

Limitations of the h-index:

• A researcher's h-index is likely to vary, depending on the database used to calculate it because the sources may have indexed a different number of the author's work.
• Early-career researchers have an h-index disadvantage.
• Cannot use h-index to compare researchers across different fields or researchers in different stages of their careers.

g-index

Proposed in 2006 as an alternative to the h-index, the g-index attempts to give more weight to highly-cited papers. The g-index remains controversial and is not yet widely accepted.

i10-index

Used only in Google Scholar, this simple index, introduced in 2011, counts the number of publications with at least 10 citations.

m-index 

The m-index takes into account years since first publication and is more relevant to an earlier career researcher than the h-index.

1. Perform an author search in the free author profile lookup form or click on an author when in Scopus

2. Select the correct author if presented with multiple names

The Author Details page will display the h-index plus summary data on documents and citation trends.

1. Enter the author's name in the top search box 
2. Select Author from the drop-down menu. Click Search.
3. Click on Citation Report on the right hand corner of the results page

Web of Science will display h-index, average citations per item, and a graph displaying publication/citation patterns:

1. Log into your Google Account and go to Google Scholar.

2. Click on My Citations.

3. Populate your profile and add your publications. Google will probably suggest many of them and ask you to confirm. Publications like theses, books, and reports that might not be included in Scopus or Web of Science can be added in Google Scholar and will contribute to your citation count. 4. You should check data in Google Scholar carefully, since it can be more prone to errors and duplication.

Exploring Citations to Your Articles in Google Scholar Citations

A Google Profile includes the h-index and i10-index and and overview of citation activity over a number of years:

Q: When looking for citation counts or h-index, is it better to use Web of Science, Scopus, or Google Scholar?

A: Since each indexes different content, it is a good idea to search all three, export the results into citation managers, and remove all duplicates.  You may also want to consult discipline-specific databases that offer citation data.

Publish or Perish is downloadable software program that uses data from Google Scholar to calculate a variety of metrics, including the h-index:

• Total number of papers and total number of citations
• Average citations per paper, citations per author, papers per author, and citations per year
• Hirsch's h-index and related parameters
• Egghe's g-index
• The contemporary h-index
• Three variations of individual h-indices
• The average annual increase in the individual h-index
• The age-weighted citation rate
• An analysis of the number of authors per paper.

The results are available on-screen and can also be copied to the Windows clipboard (for pasting into other applications) or saved to several other formats.

Advantages:

• Accesses a wide range of data not covered by other tools
• Better coverage of books, conference proceedings than WoS or similar tools

Disadvantages:

• No list of journals or other materials indexed
• No indication of time period covered
• Notably poor coverage of material only in print
• Duplicates have to be removed manually
• No means to distinguish between authors with the same initials

Publons allows you to track your publications, citations, and contributed peer reviews in one dashboard. Publons also calculates your h-index (and displays all data on a public-facing dashboard). Publons is part of Web of Science Group.