Library Help: Office For Open Research

What is the h-index?

The h-index, introduced by physicist Jorge Hirsch in 2005, is a metric that attempts to measure both the productivity and citation impact of a researcher’s work. The h-index is calculated based on a researcher’s most cited papers and the number of citations those papers have received.

A researcher has an h-index of h if they have published h papers that have each been cited at least h times. For example, an author with an h-index of 10 has published 10 papers that have each been cited at least 10 times. This aims to provide a more balanced view of a researcher’s productivity and influence, by considering both the number of publications and their impact in terms of citations.

Where and why is the h-index useful?

• Academic Impact Indicator: The h-index does provide a more holistic view of productivity than raw citation counts by considering both the quantity and quality of citations.

• Identifying Influential Researchers: The h-index can help to identify influential researchers in specific fields by comparing the impact of their work to that of their peers.

• Tracking of Progress: You can can track your own h-index over time to monitor how your academic output and citation impact are evolving.

When and why to be cautious with the h-index

While the h-index can provide indicators of academic productivity and impact, it is important to be aware that it is now widely recognised to hold a number of limitations:

• Does Not Account for Article Quality: The h-index is based on citation counts, but it does not measure the quality or significance of individual citations. A paper with 10 citations could have a substantial impact on a niche field, but this would not be reflected in the h-index.

• Disciplinary Differences: The h-index varies significantly across academic disciplines. Fields with higher citation rates, such as the life sciences, tend to have higher h-indices compared to fields with lower citation rates, such as the humanities or mathematics. As a result, the h-index is not directly comparable across disciplines without considering context.

• Ignores Author Order and Contribution: The h-index does not differentiate between the primary author and co-authors. In multi-author papers, all contributors are counted equally, even though some may have contributed more significantly to the research than others.

• Ignores Career Length: Researchers with longer careers may naturally have a higher h-index simply due to more time to accumulate citations, while newer researchers may have lower h-indices even if their work is of comparable quality.

• Vulnerable to Self-Citation and Citation Cartels: As with other citation-based metrics, the h-index can be artificially inflated by excessive self-citation or by citation cartels, where researchers agree to cite each other’s work disproportionately.

• Not a Full Measure of Impact: The h-index is a quantitative metric and does not capture the broader societal impact of research, such as influence on policy, public understanding, or innovation outside academia.

Platforms that provide the h-index

Several platforms allow researchers to calculate their h-index, each with its own strengths and limitations:

1. Scopus

   • Scopus is one of the most popular platforms for calculating the h-index. It tracks citations across peer-reviewed journals, conference proceedings, and other academic sources, providing an up-to-date view of a researcher’s academic impact.
   • Scopus provides both individual and author-level h-index scores, and it includes citation trends over time, which can be useful for monitoring changes in academic impact.
      

2. Web of Science (WoS)

   • WoS offers h-index calculations for individual researchers. It tracks citations from a variety of academic journals and provides citation data for papers published across multiple decades.
   • WoS provides an Author Impact Profile that includes h-index along with citation counts and other important metrics, although its coverage may differ from Scopus.
      

3. Google Scholar

   • Google Scholar provides h-index calculations through its freely available researcher profiles. The platform is often used by researchers who want a broader view of their citation data, including citations from non-traditional academic sources (e.g., books, theses, or conference presentations).
   • However, Google Scholar is less curated than Scopus or WoS, so the data may be less precise, with potential for skewed results from non-peer-reviewed sources.

Why the h-index varies between platforms

The h-index may differ across platforms due to several factors:

• Citation Coverage: Different databases index different sets of journals, conference proceedings, and other academic sources. For example, Scopus and Web of Science cover a slightly different set of journals, which can lead to different citation counts and h-index values.

• Time Lag: Platforms update citation counts at different intervals. Scopus and Web of Science tend to update citation data more regularly, while Google Scholar may have a lag in indexing new citations.

• Database Coverage: Some platforms, such as Google Scholar and Dimensions, index a wider range of materials, including grey literature, books, and patents, which can result in a different h-index calculation than those based solely on peer-reviewed articles.

• Self-Citations: The treatment of self-citations may vary across platforms. Some platforms, like Scopus, allow users to filter or exclude self-citations, while others, like Google Scholar, may include them in the h-index calculation.

How to Find Your h-index in Scopus

To find your h-index in Scopus, follow these steps:

1. Search for Your Author Profile:

   • Access Scopus using the link provided within Library search
   • Click on the “Author Search” tab.
   • Enter your name or ORCID ID to find your author profile. If you don’t have a profile yet, you may need to create one.
      

2. View Your Author Profile:

   • Once you locate your author profile, click on it to view your detailed information.
   • Scopus will display your citation overview, which includes your h-index, total citations, and citation trends over time.
      

3. Check the h-index:

   • Your h-index will be listed in the “Citation Overview” section of your profile. It will show the value of your h-index, along with other metrics such as total citations and the number of articles that have been cited.
   • You can view a visual represenation by clicking on the "View h-graph" option
      

4. Review Citation Data:

   • You can explore the individual articles that contributed to your h-index by looking at your publications list. The most cited papers will appear at the top, and you can see the citation count for each paper.