Skip to Main Content

Research Impact & Metrics Guide

This guide provides an introduction to research impact and an overview of select metrics used to measure research impact and their value, appropriate use, and limits.

Author Metrics

Author metrics are used to measure the impact of a specific researcher over their careers. Indices include but are not limited to:

  • Publication list: a tally of publications by an author which measures productivity but not quality or impact (Mering 2017)
  • Times cited or citation counts: the number of times an article/publication has been cited by another article/publication (Mering 2017)
  • h-index: the largest number of h papers with at least h number of citations. The h-index accounts for both the quality and the quantity of a researcher’s publications (Downey 2023). For example, if your h-index score is 97, that means you have at least 97 papers/articles that have been cited by at least 97 other papers/articles. (Hirsch 2005)

It is important to remember that while there are several different methods of measuring and evaluating one’s impact, no one specific indicator will provide the full picture (Roemer 2015, Downey 2023). For information on additional author metrics, see the chapter by Downey (2023).

Notes

  • The term “author” can be used interchangeably with researcher, academic, scholar, or equivalent.
  • The importance of the author maintaining accurate and current author profiles cannot be overemphasized! An updated and vetted author profile increases your visibility to grant funders and potential collaborators, attributes your scholarly activities to you and improves the accuracy of author level metrics. Please refer to the guide below for information on the different author profiles, related resources, and how to keep your profiles updated with your publications and scholarly activities.

The h-index is the most widely known, discussed, and used index for measuring academic author productivity. Devised in 2005 by the American physicist, Jorge E. Hirsch, the h-index answers the question, "How does one quantify the cumulative impact and relevance of an individual’s scientific research output?" By accounting for both the quality and the quantity of a researcher’s publications, the h-index provides a more accurate, more objective and thus more readily comparable evaluation basis for the academic significance of individual authors. (Ball 2017, Downey 2023, Hirsch 2005)

The h-index is determined by sorting all the publications by a person in the descending order of their citation frequency. The value where the sequential number of the publication tallies with the citation frequency denotes the Hirsch factor. Low and high extremes are disregarded in favor of the "broadest" possible performance record. The h-index says something about both the productivity and the influence of a scientist. (Ball 2017). For example, if your h-index score is 97, that means you have at least 97 papers/articles that have been cited by at least 97 other papers/articles. (Hirsch 2005)

Hirsch noted the following caveats:

  • A single number can never give more than a rough approximation to an individual’s multifaceted profile. Many other factors should be considered in combination in evaluating an individual.
  • The h-index cannot be used to compare researchers in different disciplines. Between disciplines, there are differences in the average number of references in a paper in the field, the average number of papers produced by each scientist in the field, and the size (number of scientists) of the field.
  • While a high h is a reliable indicator of high accomplishment, the converse is not necessarily always true. There is considerable variation in the skewness of citation distributions even within a given subfield, and for an author with a relatively low h that has a few seminal papers with extraordinarily high citation counts, the h index will not fully reflect that scientist’s accomplishments.

Roemer and Borchardt (2015) note additional caveats:

  • Early career researchers can be at a disadvantage since the more prolific the author, the higher the potential for the h-index value.
  • The h-index does not account for works other than articles or citations that appear outside of articles.

The h-index can be found in the Web of Science, Scopus, and Google. When reviewing the h-index generated by each database (Li 2010, Minasny 2013), it is important to understand the:

  • Scope of publication coverage by disciplines
  • Quality of publication
  • Publication timeframe coverage
  • Citation analysis capabilities
  • Accuracy of the citations attributed to you – an inaccurate h-index will be calculated if you are listed in the database with name variants or have multiple or unclaimed author profiles.

Scopus is a multidisciplinary scientific database with content covering over 97 million records from over 28,000 serial titles across 7,000 publishers in the physical sciences, health sciences, life sciences, and social sciences (as of July 2024). The database includes journal articles, pre-prints, books, patents, conference proceedings, and more.

How can I search for an author?

Use the Authors tab to search for a specific author. You can search for an author by name, ORCID ID, or keyword (use keywords related to a research area, topic, or interest).

The Author Profile metrics include:

  • Number of publications
  • h-index – Scopus is currently updating pre-1996 cited references going back to 1970, and the h-index might increase over time.
  • Number of times they have been cited
  • Author's most contributed topics – Scopus defines topic as “a collection of publications with a common focused intellectual interest”.

Other metrics include:

  • Collaboration – includes internation collaboration (percent of documents co-authored with researchers in other countries/regions) and academic-corporate collaboration (percent of documents with both academic and corporate affiliations)
  • Documents in top citation percentiles – percent of documents in the top 25% most cited documents worldwide
  • Documents in the top 25% of journals by CiteScore percentile
  • Documents and Field-Weighted Citation Impact (FWCI) – the FWCI is the ratio of citations received relative to the expected world average for the subject field, publication type, and publication year.

How can I check if my h-index is correct?

Your h-index relies on two key pieces of information for its accuracy:

  1. The documents you published must be linked to your profile
  2. Citations of your documents must be linked in Scopus

Need help using Scopus?

The Web of Science Core Collection indexes more than 22,000 peer-reviewed journals in the sciences, social sciences, and arts and humanities, as well as international proceedings and book content. The database contains over 91 million records for journal, conference, and book content.

How can I search for an author?

Use Researcher Search to search for author records and profiles of researchers across the Web of Science Core Collection, and this option helps identify articles likely authored by the same person and view profiles for those authors that contain metrics and other scholarly activity (for example, peer review).

You can search for an author by name or their author identifier (Web of Science ResearcherID or ORCID).

The metrics in the author record are derived from citations awarded only to your Web of Science Core Collection indexed papers. The metrics are located in the right-hand column and include:

  • h-Index – you have an h-Index of N if you have at least N publications with at least N citations.
  • Publications in Web of Science – the number of publications on your profile which are indexed in the Web of Science Core Collection.
  • Sum of Times Cited – the sum of citations your Web of Science Core Collection documents have received from the Web of Science Core Collection.
  • Citing Articles – the number of documents in the Web of Science Core Collection which have cited the Web of Science Core Collection documents on your profile.

Below the metrics is the Author Impact Beamplot Summary, which is built on a researcher’s articles and review documents over their career.

Need help using Web of Science?

In addition, users may click the following link to register for full access to a white paper from Clarivate Analytics:

Google Scholar encompasses a wide range of scholarly materials, including articles, theses, books, abstracts, and even court opinions, sourced from various academic publishers, professional organizations, online archives, universities, and other websites.

Content – includes articles, theses, books, abstracts and court opinions, from academic publishers, professional societies, online repositories, universities and other web sites.

Metrics – provide an easy way for authors to quickly gauge the visibility and influence of recent articles in scholarly publications.

Coverage – Scholar Metrics currently covers articles published in the last five years. For example, the current date range is between 2019 and 2023, both inclusive. The metrics are based on citations from all articles that were indexed in Google Scholar in July 2024.

How can I search for an author?

  1. Type the author’s name in the Google Scholar search box.
  2. Click on the author’s name link to view the author metrics:
    • Number of Citations
    • h-index
    • i10-index = the number of publications with at least 10 citations and is unique to Google Scholar. The i10-index is exclusively used within Google Scholar Profiles. For example, if a researcher has 26 articles with at least 10 citations, the i10-index is equal to 26.

Note: The timeframe for the citation analysis will be stated (i.e., "Since 20XX").

As a backdrop, Loan et al (2022) summarizes the practices and evidence of how Google Scholar metrics have been manipulated using self-citations, fake researchers, mock publications, and reviewer compulsions, coercive citations, merging articles and splitting articles. Their study identified another dangerous method of manipulation: i.e., false authorship claims. This puts a big question mark on the reliability of the Google Scholar bibliometric indicators.

Need help using Google Scholar?

References

Ball, R. (2017). Introduction to bibliometrics: new development and trends. Chandos Publishing, an imprint of Elsevier. https://www.sciencedirect.com/science/book/9780081021507

Downey, K. J. (2023). Author metrics. In M. R. Dreker & K. J. Downey (Eds.), Building your academic research digital identity: A step-wise guide to cultivating your academic research career online (pp. 69-83). Springer Nature Switzerland. https://doi.org/10.1007/978-3-031-50317-7_6

Hirsch, J. E. (2005). An index to quantify an individual's scientific research output. Proceedings of the National Academy of Sciences of the United States of America, 102(46), 16569-16572. https://doi.org/10.1073/pnas.0507655102

Loan, F. A., Nasreen, N., & Bashir, B. (2022). Do authors play fair or manipulate Google Scholar h-index?. Library Hi Tech, 40(3), 676-684. https://doi.org/10.1108/LHT-04-2021-0141

Martín-Martín, A., Orduna-Malea, E., Thelwall, M., & Delgado López-Cózar, E. (2018). Google Scholar, Web of Science, and Scopus: A systematic comparison of citations in 252 subject categories [Article]. Journal of Informetrics, 12(4), 1160-1177. https://doi.org/10.1016/j.joi.2018.09.002

Roemer, R. C., & Borchardt, R. (2015). Meaningful metrics: A 21st century librarian’s guide to bibliometrics, altmetrics, and research impact. Association of College and Research Libraries, a division of the American Library Association.
Available as an Open Access Publication from ACRL