h index researchgate

• Publication Recognition

What is a Good H-index?

• 4 minute read
• 358.1K views

Table of Contents

You have finally overcome the exhausting process of a successful paper publication and are just thinking that it’s time to relax for a while. Maybe you are right to do so, but don’t take very long…you see, just like the research process itself, pursuing a career as an author of published works is also about expecting results. In other words, today there are tools that can tell you if your publication(s) is/are impacting the number of people you believed it would (or not). One of the most common tools researchers use is the H-index score.

Knowing how impactful your publications are among your audience is key to defining your individual performance as a researcher and author. This helps the scientific community compare professionals in the same research field (and career length). Although scoring intellectual activities is often an issue of debate, it also brings its own benefits:

• Inside the scientific community: A standardization of researchers’ performances can be useful for comparison between them, within their field of research. For example, H-index scores are commonly used in the recruitment processes for academic positions and taken into consideration when applying for academic or research grants. At the end of the day, the H-index is used as a sign of self-worth for scholars in almost every field of research.
• In an individual point of view: Knowing the impact of your work among the target audience is especially important in the academic world. With careful analysis and the right amount of reflection, the H-index can give you clues and ideas on how to design and implement future projects. If your paper is not being cited as much as you expected, try to find out what the problem might have been. For example, was the research content irrelevant for the audience? Was the selected journal wrong for your paper? Was the text poorly written? For the latter, consider Elsevier’s text editing and translation services in order to improve your chances of being cited by other authors and improving your H-index.

What is my H-index?

Basically, the H-index score is a standard scholarly metric in which the number of published papers, and the number of times their author is cited, is put into relation. The formula is based on the number of papers (H) that have been cited, and how often, compared to those that have not been cited (or cited as much). See the table below as a practical example:

In this case, the researcher scored an H-index of 6, since he has 6 publications that have been cited at least 6 times. The remaining articles, or those that have not yet reached 6 citations, are left aside.

A good H-index score depends not only on a prolific output but also on a large number of citations by other authors. It is important, therefore, that your research reaches a wide audience, preferably one to whom your topic is particularly interesting or relevant, in a clear, high-quality text. Young researchers and inexperienced scholars often look for articles that offer academic security by leaving no room for doubts or misinterpretations.

What is a good H-Index score journal?

Journals also have their own H-Index scores. Publishing in a high H-index journal maximizes your chances of being cited by other authors and, consequently, may improve your own personal H-index score. Some of the “giants” in the highest H-index scores are journals from top universities, like Oxford University, with the highest score being 146, according to Google Scholar.

Knowing the H-index score of journals of interest is useful when searching for the right one to publish your next paper. Even if you are just starting as an author, and you still don’t have your own H-index score, you may want to start in the right place to skyrocket your self-worth.

See below some of the most commonly used databases that help authors find their H-index values:

• Elsevier’s Scopus : Includes Citation Tracker, a feature that shows how often an author has been cited. To this day, it is the largest abstract and citation database of peer-reviewed literature.
• Clarivate Analytics Web of Science : a digital platform that provides the H-index with its Citation Reports feature
• Google Scholar : a growing database that calculates H-index scores for those who have a profile.

Maximize the impact of your research by publishing high-quality articles. A richly edited text with flawless grammar may be all you need to capture the eye of other authors and researchers in your field. With Elsevier, you have the guarantee of excellent output, no matter the topic or your target journal.

Language Editing Services by Elsevier Author Services:

What is a Corresponding Author?

• Manuscript Review

Systematic Review VS Meta-Analysis

You may also like.

How to Make a PowerPoint Presentation of Your Research Paper

How to Submit a Paper for Publication in a Journal

Input your search keywords and press Enter.

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• J Family Med Prim Care
• v.12(11); 2023 Nov
• PMC10771139

The h-Index: Understanding its predictors, significance, and criticism

Himel mondal.

1 Department of Physiology, All India Institute of Medical Sciences, Deoghar, Jharkhand, India

Kishore Kumar Deepak

2 Centre for Biomedical Engineering, Indian Institute of Technology, New Delhi, India

Manisha Gupta

3 Department of Physiology, Santosh Medical College, Santosh University, Ghaziabad, Uttar Pradesh, India

Raman Kumar

4 National President and Founder, Academy of Family Physicians of India, India

The h-index is an author-level scientometric index used to gauge the significance of a researcher's work. The index is determined by taking the number of publications and the number of times these publications have been cited by others. Although it is widely used in academia, many authors find its calculation confusing. There are websites such as Google Scholar, Scopus, Web of Science (WOS), and Vidwan that provide the h-index of an author. As this metrics is frequently used by recruiting agency and grant approving authority to see the output of researchers, the authors need to know in-depth about it. In this article, we describe both the manual calculation method of the h-index and the details of websites that provide an automated calculation. We discuss the advantages and disadvantages of the h-index and the factors that determine the h-index of an author. Overall, this article serves as a comprehensive guide for novice authors seeking to understand the h-index and its significance in academia.

Introduction

The h-index is a commonly used metric to measure the productivity and impact of academic researchers. It was first introduced in 2005, and since then, the h-index has become an important tool for evaluating researchers, departments, and institutions.[ 1 ] The calculation of the h-index is relatively simple, yet it confuses novice authors. There are several websites where researchers can find their h-index autocalculated. While the h-index has several advantages, such as providing a simple and objective measure of a researcher's impact, there are also some limitations to its use. For example, the h-index does not take into account the quality of the publications or the context in which they were cited.[ 2 ]

In this study, we will explore the calculation of the h-index, the websites where it is available, and the advantages and disadvantages of using this metric, and it is predictors that increase the h-index of an author. By examining the strengths and weaknesses of the h-index, we hope to provide a comprehensive understanding of this important tool for evaluating scientific impact.

Calculation Method

The h-index is defined as the “highest number h, such that the individual has published h papers that have each been cited at least h times.”[ 3 ] For example, if an author has 10 papers and seven of those have been cited at least seven times each, then the h-index for that individual is 7. To make it more easy, we are presenting an example of how an author can calculate the h-index manually [ Table 1 ]. To calculate the h-index, we first sort the papers in descending order based on their citation counts. Then, we count the number of papers that have at least as many citations as their position in the list. The table footnote describes situations where the h-index would be 8 or 9 in future.

h-index of an author who has 10 papers

The h-index of the author is 7. A total of seven of the papers got at least seven citations each. Eight of the papers have not received at least eight citations. The author's h-index will be 8 when “Paper 8” gets additional three or more than three citations. The author's h-index will be 9 when “Paper 7” gets additional one or more than one, “Paper 8” gets additional four or more than four, and “Paper 9” gets additional five or more than five citations

Where to Get h-Index?

There are databases that provide the h-index information for authors for free. Some of the most commonly used websites that calculate the h-index of an author are listed as follows. The website titles, links, and services that are freely available are shown in Table 2 .

Websites that calculate the h-index of an author

WOS: Web of Science

Google Scholar

Perhaps it is the most commonly used website by scholars around the world. Google Scholar provides h-index information for authors based on the citations of their papers as indexed by Google Scholar.[ 4 ] It is a free service provided by Google Scholar, and any researcher can open an account. However, if the researcher has an institutional email address, then the account can be made public after verifying the email. The authors can observe the year-wise citation count for a quick idea about the trend of citations over the years. An example is shown in Figure 1 a.

Examples of h-index of an author found in (a) Google Scholar, (b) Scopus, (c) Web of Science, and (d) ResearchGate showing discordance in h-index

This database, provided by Elsevier, is another popular citation database that provides h-index information and other metrics, such as total citations and year-wise citations.[ 5 ] Researchers can search for any name from the home page by clicking on “View your author profile” and searching by surname and name. However, we suggest creating a free account to track your own articles and citations. An example is shown in Figure 1 b. From the same homepage, the authors can also check the articles published and citation count of any journal by clicking on “View journal rankings.”

Web of Science

This database is maintained by Clarivate, and it is one of the most widely used citation databases. Previously, Researcher ID was provided by Thomson Reuters.[ 6 ] Now, the Researcher ID is provided by Web of Science (WOS) that is maintained by the parent company Clarivate. The creation of an account is free in WOS. After creating the account, an author can view own details and also search for other researchers in the database. In the profile, WOS provides h-index information and other metrics, such as total citations, number of WOS-indexed articles, and number of citing articles. An example is shown in Figure 1 c.

ResearchGate

This social networking site for researchers provides h-index information and other metrics, such as total citations and year-wise citations. To get the h-index in ResearchGate, one needs to create an account.[ 7 ] Only published authors or invitee can create an account. Although ResearchGate suggests using the institutional email address, without it authors can open an account too. The authors need to send proof of publication for the creation of an account by a noninstitutional email address. In addition, those who are already in ResearchGate can send invitation to others to open an account. After logging in, the h-index is shown along with other metrics as shown in Figure 1 d.

The Vidwan Expert Database and National Researcher's Network is a comprehensive platform designed to connect and showcase the expertise of scholars and researchers across various fields. It is a service provided by the Information and Communications Technology of Ministry of Education, India. The database is developed and maintained by the Information and Library Network Centre (INFLIBNET). This service is not open to all authors. Any recipient of national or internal award, any postgraduate with 10 years of professional experience, postdoctoral fellow, research scholar, professor (full, associate, or assistant), senior scientist, or having equivalent reaching or research post can open an account. This website shows the h-index along with total articles, year-wise articles, type of publication, total citations, citations available from Crossref ( https://www.crossref.org ), number of coauthors, coauthor network, and Altmetric ( https://www.altmetric.com ) scores. A part of the Vidwan profile with the h-index of a researcher is shown in Figure 2 .

A part of a Vidwan profile showing the h-index and other metrics of the second author

Why h-Index Differ?

The h-index can differ between different sites. One can see her/his h-index higher in Google Scholar than in Scopus or WOS.[ 8 ]

Different databases may have different coverage and indexing policies. Some databases may include more or fewer journals, conference proceedings, or other sources of academic literature. This can affect the number of citations that are included in the h-index calculation.

Different databases may have different time lags in their citation data, meaning that citations may not be indexed at the same time or may be indexed differently based on the date of publication. This can affect the h-index calculation for a temporary period, especially if a researcher has recently published a highly cited paper that has not yet been indexed by a particular database.

In addition to the above factors, there may be errors or inconsistencies in the citation data used to calculate the h-index, which can lead to differences in the resulting h-index across different databases.

Therefore, it is important to use multiple sources of h-index information and to be aware of the potential differences between different sites. Google Scholar uses maximum sources to calculate the h-index. Hence, the h-index in Google Scholar may be the highest among the h-index provided by other databases. One question may still ponder: Which to take as the final h-index of an author? Although there is no simple answer to this question, Google Scholar may be considered the provider of the most comprehensive h-index. The impact of research is now not limited to citation in a journal article indexed by a single bibliographic database.

Advantages of h-Index

The h-index has several advantages as a measure of research productivity and impact. The h-index takes into account both the number of publications and the number of citations those publications have received. This helps to balance the impact of quantity (by number of publications) and quality of publications (by number of citations it received) on the researcher's overall research output. The h-index can be easily calculated using citation databases, such as Google Scholar. Being a free service, any author can get the h-index automatically calculated in Google Scholar. Scopus and WOS also provide their services free of charge for getting the h-index. We can use the h-index to compare the productivity and impact of researchers across different disciplines. The h-index is less affected by outliers. The h-index is less sensitive to individual highly cited papers or lowly cited papers, as it considers the total number of papers a researcher has published that have been cited a certain number of times. It provides a long-term measure of research impact, as it takes into account the entire career of the researcher rather than just a single paper or a recent burst of activity.[ 9 ]

Limitation of h-Index

Despite these advantages, the h-index is not without limitations. The h-index is criticized for favoring researchers who have been in the field for a longer period of time, as they have had more time to publish and accumulate citations. This can disadvantage early-career researchers. The h-index does not account for differences in citation practices between different fields or subfields, which can lead to unfair comparisons between researchers in different areas. The h-index relies on citation databases, which may not include all relevant citations. This can result in an inaccurate representation of a researcher's impact. However, this is common for all online calculated indices. The h-index includes citations to a researcher's own work, which can inflate the researcher's impact and may not accurately reflect their influence on the field. The h-index can be manipulated by self-citing excessively to increase the number of citations. The h-index does not take into account other important factors, such as the quality of publications, the impact of a researcher's work beyond citations, or their contributions to teaching and service.[ 10 ]

Hence, the h-index should be used in conjunction with other metrics and qualitative evaluations to get a comprehensive assessment of a researcher's productivity and impact.

Usage of h-Index in Academia

There is no thumb rule of the level of h-index for hiring professionals or promotion of faculties. However, this index can be used by the universities for comparison of impact among the candidates for hiring or promotion. In addition, universities are commonly interested in recruiting a researcher with higher publication impact as the impact would be a feather to the crown of the university. A study by Wang et al .[ 11 ] in the Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama, United States, found that a faculty has a median h-index of 6 at hiring, 11 during the promotion from assistant to associate professor, and 17 during the promotion from associate to full professor. In addition, Schreiber and Giustini studied 14 disciplines in North American medical schools and found that assistant professors have an h-index of 2 to 5, associate professors have 6 to 10, and full professors have an index of 12 to 24.[ 12 ] A study by Kaur from India showed that top publishing authors in the medical field from All India Institute of Medical Sciences, Delhi, and Postgraduate Institute of Medical Education and Research, Chandigarh, have the h-index of 15 and 21, respectively.[ 13 ] Nowak et al .[ 14 ] analyzed 13 medical specialties and found that the median h-index was 19.5. There is a need for further research and reviews to get a generalizable result. Till we get that, the rule is “the more the merrier!”

Other Numbers and Indices Used in Academia

There are other author-level metrics that are used by various universities to evaluate research productivity and impact.

Some universities still use the total number of publications as a criterion for promotion. In addition, the total number of citations is also considered an indicator of research impact. This metric counts the total number of times an author's papers have been cited, regardless of the number of papers they have published. Furthermore, the average number of citations per paper for an author, which can provide insight into the overall quality and impact of their work, is sometimes considered. Table 3 shows the various other calculations and indices that are used.

Other calculations and indices (calculated from data in Table 1 )

The i10-index is another simple measure that indicates the number of papers that have received 10 citations each. It is shown in a Google Scholar profile along with the h-index of an author [ Figure 1 a].

The g-index is another metric that is not readily found calculated in the above database websites, but one can manually calculate the g-index of an author. It gives more weight to highly cited papers. It is calculated by finding the largest number of g such that the top g papers have a total of at least g 2 citations. For example, in Table 1 , the author had a g-index of 10 as cumulative citations on the 10 th paper are more than 10 2 [ Table 2 ]. If the author had a 11 th paper with even 0 citations, the g-index would be 11 (as cumulative citations are more than 11 2 ). However, if the author had a 12 th paper with 0 citations, the g-index could be 11 as cumulative citations were below 12 2 .[ 3 ]

The m-index is a metric that takes into account the h-index and years of activity of an author.[ 15 ] Its calculation is simple. For example, if the author is publishing the papers shown in Table 1 for the last 5 years, the m-value or m-index would be 1.4 (7/5) [ Table 3 ].

It is important to note that no single metric can provide a comprehensive evaluation of a researcher's productivity and impact, and these metrics should be used in combination with other qualitative evaluations. Furthermore, no index is still there in academia that is capable of judging the quality of a research paper.

Factors that Influence h-Index

Achieving a high h-index can be a long-term process that requires sustained research productivity and impact.[ 16 ] Here are some factors that have the potential to influence the h-index.

Publish in high-impact journals

Publishing in high-impact journals can help to increase the visibility and impact of one's research, leading to more citations and a higher h-index. High-impact journals are typically those with a large readership and reputation for publishing groundbreaking research. Articles published in these journals tend to be highly cited and can have a significant impact on their respective fields.[ 17 ]

Make research openly accessible

Making research freely and openly accessible can increase the visibility and impact of one's work, leading to more citations and a higher h-index. Open-access articles can reach a wider audience and potential readership, including researchers who might not have access to the article through traditional subscription-based methods. Additionally, open-access articles can be easily shared on social media platforms, blogs, and other online forums, which can increase their reach and promote their visibility.[ 18 ]

Collaborate with other researchers

Collaborating with other researchers can lead to more publications and citations, as well as exposure to new research ideas and methods. Collaboration can bring together researchers with different areas of expertise and skill sets, resulting in more comprehensive and impactful research. Collaborating with other researchers can increase the visibility of the research. Collaborators are likely to share the research with their networks, potentially increasing the readership and citations of the work.[ 19 ]

Balance quality and quantity

While the quantity of publications is important, it is more important to focus on producing high-quality research that is impactful and well-regarded in the field. Higher-quality articles are more likely to be cited by other researchers, which can further increase their impact and visibility.[ 20 ] However, the number is also important. For example, if an author has five papers with a huge 50000 citations, the h-index would be 5 only.

Stay active in the field

Attending conferences can provide opportunities to meet other researchers and learn about new research in the field. By presenting one's own research at a conference, researchers can receive feedback and ideas from other scholars, which can lead to new collaborations and research opportunities. Attending conferences also provides opportunities to network with other researchers. Delivering talks or lectures can also increase visibility and impact. Participating in scholarly discussions, such as by commenting on blogs or participating in online forums, can also increase visibility, which increases the chances of higher citations.[ 21 ]

Promote your research

Promoting research can be an effective strategy for increasing citations. There are several ways to promote research, including sharing it on social media, collaborating with other researchers, and seeking media coverage. Sharing research on social media can be an effective way to increase visibility and reach a wider audience. Researchers can share their work on their personal or professional social media accounts or on specialized platforms, such as ResearchGate or Academia.edu.[ 22 ] Seeking media coverage can also be an effective way to promote research and increase citations. Media coverage can increase the visibility of the research and attract the attention of other researchers who may be interested in citing the work. Researchers can also promote the articles on their own websites for a higher reach in the field, which lead to more citations and a higher h-index.[ 21 ]

Conduct timely research

By working on influential research and trending topics, researchers can increase the likelihood that their work will be cited by other researchers in the field. To conduct timely research, researchers need to stay up-to-date on the latest developments and emerging trends in their field. This may involve reading relevant literature, attending conferences, and collaborating with other researchers. By staying current with the latest research, researchers can identify gaps in the field and opportunities for making meaningful contributions.[ 23 ]

It is important to note that these strategies should not be used to game the system or artificially inflate one's h-index, but rather as ways to increase the impact and visibility of one's research in a genuine and sustainable way.

Institutional Level Data

The institutional h-index is not readily available in Google Scholar. However, one can manually search the total publications from the institution and citation to the published article from the institutional repository (if available) to calculate the h-index of the institution. The calculation method remains the same. Institutions that do not have their own repository can collect data from Google Scholar about publications and citations. If the institution provides an email address to the employee, and teachers or researchers verify the email address, the data can be collected from Google Scholar from the following method. The website https://scholar.google.com/citations?mauthors=aiimsdeoghar.edu.in&hl=en&view_op=search_authors is opened if the institution has the Uniform Resource Locator (URL) as aiimsdeoghar.edu.in. All the authors who verified their accounts would be shown with their papers and citations.[ 24 ] These data can be used to calculate the central tendencies of the h-index of the authors in that institution. A similar method can be used to extract data from other databases, such as Scopus, to compute the institution-level h-index.[ 25 ] Institutions may also open a user account as a researcher in Google Scholar as shown in Figure 3 and add the published “Add article manually” (after clicking the addition “+” button) to get institutional level h-index.

A profile of an institution in Google Scholar

The h-index of global institutions can also be found at https://exaly.com/institutions/citations . This website hosts data of 53,307 institutions along with their h-index. Exaly is a nonprofit initiative aimed at filling the gap of lacking an inclusive and accessible collection of academic papers and scientometric information. It is referred to as a project rather than an organization to ensure independence from commercial motives. Indian regional data are available on a website https://www.indianscience.net/list_inst.php that provides data till 2019 . This website extracted data from Dimensions ( https://www.dimensions.ai ) and Altmetric ( https://www.altmetric.com ).[ 26 ]

In conclusion, the h-index is a widely used metric for measuring the productivity and impact of researchers. While it has some limitations, such as its inability to capture the quality of publications and the potential for manipulation, the h-index remains a useful tool for evaluating the performance of individual authors and comparing researchers and institutions. Hence, the potential predictors of the index were discussed along with its calculation methods. The h-index in conjunction with other metrics and factors for evaluating research productivity and impact was also highlighted.

Self-Assessment Multiple-Choice Questions

Five questions are available in Table 4 for self-assessment of your learning from this article.

Self-assessment multiple-choice questions

Q1: The correct answer is D. Google Scholar, Scopus, and Web of Science show the h-index of an author

Q2: The correct answer is D. We need the total papers and their citations to be arranged in higher to lower order for ease of identification of the h-index.

Q3: The correct answer is C. Three papers of the author have received at least three citations each.

Q4: The correct answer is B. Six papers of the author have received at least six citations each.

Q5: The correct answer is D. The h-index only takes papers and their citations. m-value considers the years of activity of an author

Financial support and sponsorship

Conflicts of interest.

There are no conflicts of interest.

• Maps & Floorplans
• Libraries A-Z

• Ellis Library (main)
• Engineering Library
• Geological Sciences
• Journalism Library
• Law Library
• Mathematical Sciences
• MU Digital Collections
• Veterinary Medical
• More Libraries...
• Instructional Services
• Course Reserves
• Course Guides
• Schedule a Library Class
• Class Assessment Forms
• Recordings & Tutorials
• Research & Writing Help
• More class resources
• Places to Study
• Borrow, Request & Renew
• Call Numbers
• Computers, Printers, Scanners & Software
• Digital Media Lab
• Equipment Lending: Laptops, cameras, etc.
• Subject Librarians
• Writing Tutors
• More In the Library...
• Undergraduate Students
• Graduate Students
• Faculty & Staff
• Researcher Support
• Distance Learners
• International Students
• More Services for...
• View my MU Libraries Account (login & click on My Library Account)
• View my MOBIUS Checkouts
• Renew my Books (login & click on My Loans)
• Place a Hold on a Book
• Request Books from Depository
• View my ILL@MU Account
• Set Up Alerts in Databases
• More Account Information...

Maximizing your research identity and impact

• Researcher Profiles
• h-index for resesarchers-definition

h-index for journals

H-index for institutions, computing your own h-index, ways to increase your h-index, limitations of the h-index, variations of the h-index.

• Using Scopus to find a researcher's h-index
• Additional resources for finding a researcher's h-index
• Journal Impact Factor & other journal rankings
• Altmetrics This link opens in a new window
• Research Repositories
• Open Access This link opens in a new window
• Methods for increasing researcher impact & visibility

h-index for researchers-definition

• The h-index is a measure used to indicate the impact and productivity of a researcher based on how often his/her publications have been cited.
• The physicist, Jorge E. Hirsch, provides the following definition for the h-index:  A scientist has index h if  h of his/her N p  papers have at least h citations each, and the other (N p  − h) papers have no more than h citations each. (Hirsch, JE (15 November 2005) PNAS 102 (46) 16569-16572)
• The h -index is based on the highest number of papers written by the author that have had at least the same number of citations.
• A researcher with an h-index of 6 has published six papers that have been cited at least six times by other scholars.  This researcher may have published more than six papers, but only six of them have been cited six or more times. 

Whether or not a h-index is considered strong, weak or average depends on the researcher's field of study and how long they have been active.  The h-index of an individual should be considered in the context of the h-indices of equivalent researchers in the same field of study.

Definition :  The h-index of a publication is the largest number h such that at least h articles in that publication were cited at least h times each. For example, a journal with a h-index of 20 has published 20 articles that have been cited 20 or more times.

Available from:

• SJR (Scimago Journal & Country Rank)

Whether or not a h-index is considered strong, weak or average depends on the discipline the journal covers and how long it has published. The h-index of a journal should be considered in the context of the h-indices of other journals in similar disciplines.

Definition :  The h-index of an institution is the largest number h such that at least h articles published by researchers at the institution were cited at least h times each. For example, if an institution has a h-index of 200 it's researchers have published 200 articles that have been cited 200 or more times.

Available from: exaly

In a spreadsheet, list the number of times each of your publications has been cited by other scholars. 

Sort the spreadsheet in descending order by the number of  times each publication is cited.  Then start counting down until the article number is equal to or not greater than the times cited.

Article                   Times Cited

1                              50          

2                              15          

3                              12

4                              10

5                              8

6                              7              == =>h index is 6

7                              5             

8                              1

How to successfully boost your h-index (enago academy, 2019)

Glänzel, Wolfgang On the Opportunities and Limitations of the H-index. , 2006

• h -index based upon data from the last 5 years
•  i-10 index is the number of articles by an author that have at least ten citations. 
•  i-10 index was created by Google Scholar .
• Used to compare researchers with different lengths of publication history
• m-index =   ­­­­­­­­­­­­­­­­­­___________ h-index _______________                      # of years since author’s 1 st publication

Using Scopus to find an researcher's h-index

Additional resources for finding a researcher's h-index.

Web of Science Core Collection or Web of Science All Databases

• Perform an author search
• Create a citation report for that author.
• The h-index will be listed in the report.

Set up your author profile in the following three resources.  Each resource will compute your h-index.  Your h-index may vary since each of these sites collects data from different resources.

• Google Scholar Citations Computes h-index based on publications and cited references in Google Scholar .
• Researcher ID
• Computes h-index based on publications and cited references in the last 20 years of Web of Science .
• << Previous: Researcher Profiles
• Next: Journal Impact Factor & other journal rankings >>
• Last Updated: Nov 15, 2023 11:59 AM
• URL: https://libraryguides.missouri.edu/researchidentity

tree-logo-small-v2.png

• Research trends reports
• Tips & Tricks

You are here

Search this blog, get our newsletter.

Follow Scopus

• Content (59)
• Metrics (44)
• Release (36)
• Tips and Tricks (26)
• scopus (19)

Recent Posts

• Enhancements to Citation Overview on Scopus
• ACRL Webinar - Unlocking Insights with Generative AI: How to Enhance Research Efficiency in the Library
• Changes to Scopus Open Access (OA) document tagging
• A.T. Still University Scopus and Digital Commons case study now available!
• Meet the CSAB: Professor & Subject Chair Jaya Raju

The Scopus h-index, what’s it all about? Part I

Many of the questions we receive are related to the h -index. Today we bring you a guest post by Meshna Koren, Second Line Support Manager for Scopus (also known as "she who knows all about Scopus").

h-index.jpg

The h -index is an index that attempts to measure both the productivity and impact of the published work of a scientist or scholar. In Scopus, the h -index is not a static value; it is calculated live on a set of results each time you look it up. The calculation was suggested by Hirsch and it can be summed up as:

A scientist has an index h if h of his/her Np papers has at least h citations each, and the other (Np h) papers have no more than h citations each .

In Scopus you can calculate it on any set of results; it does not have to be papers belonging to just one author. Just run a random search: TITLE-ABS-KEY(mars water ice) , select all results, click View Citation Overview and therein you will see the h -index value for that set (see image).

This means that 84 documents from this set have been cited at least 84 times, but the 85 th  document has been cited less than 85 times. Tomorrow we may load new articles (Scopus loads new content daily!) which cite any one article in this set, and the h -index may rise because of that.

What you do need to know about Scopus is that we do not have references for records of articles that have been published prior to 1996 (though this will be changing in the relatively near future, read more on the Scopus Cited References Expansion project!).

The references are needed to calculate citations; if my article A cites your article B, but Scopus doesn't have references of my article A, well, your B won't show as being cited. There's no danger if you published in 1996 or later because you couldn't have been cited before that time, but if you published in 1982 we may be showing a lower citation count for that article. And if you look at the above screenshot again, we do warn you there: "Scopus does not have complete citation information for articles published before 1996."

Check back tomorrow for Part II of “The Scopus h -index, what’s it all about? ” when we focus on calculating an individual author’s h -index.

Four problems of the h -index for assessing the research productivity and impact of individual authors

• Open access
• Published: 12 March 2022
• Volume 128 , pages 2677–2691, ( 2023 )

Cite this article

You have full access to this open access article

• Henry H. Bi   ORCID: orcid.org/0000-0001-5408-8704 1  

4905 Accesses

6 Citations

1 Altmetric

Explore all metrics

A Correction to this article was published on 25 February 2023

A Correction to this article was published on 14 July 2022

This article has been updated

This paper reveals that when the h -index is used to assess the research productivity and impact of individual authors, four major problems exist because the h -index does not take into account the number of authors in each publication. This paper shows that the fractional h -index (or the individual h i -index in this paper), which distributes each publication’s received citations among its authors, can solve these problems effectively. This paper recommends that websites (such as scholar.google.com and researchgate.net) should add the h i -index for the sake of building a fairer and more ethical research community.

Similar content being viewed by others

Multiple versions of the h-index: cautionary use for formal academic purposes

Rejoinder to “multiple versions of the h-index: cautionary use for formal academic purposes”.

Authorship and citation patterns of highly cited biomedical researchers: a cross-sectional study

Avoid common mistakes on your manuscript.

Problems of using the h -index to assess the research productivity and impact of authors

The h -index (Hirsch, 2005 ) has been widely used to assess the productivity and impact of journals (such as www.scimagojr.com) and authors (such as scholar.google.com and researchgate.net). Because a citation is a reference in a publication to another publication, it is appropriate to use the h -index to assess a journal’s productivity and impact based on its number of publications ( h ) that have received at least h citations each.

However, because the h -index does not take into account the number of authors in each publication (Schubert & Schubert, 2019 ), the following four problems exist in the research community when the h -index is used to assess each author’s research productivity and impact:

Problem #1–individually taking full credit for a multiauthored publication’s all contributions. A multiauthored publication is generated by intellectual contributions from multiple authors. Each citation cites a multiauthored publication as a whole, not each of its authors. When the number of all citations that a multiauthored publication has received is used in computing an individual author’s h -index, it means that this author takes full credit for this publication’s all contributions (including those from other authors), which is fundamentally and ethically improper.

Problem #2–creating inflation in counting citations. When the h -index is used to assess the research productivity and impact of authors, it also creates a problem of “inflation in counting citations”. For instance, suppose that a three-authored publication has received 60 citations. If each of these three authors credits this publication’s all 60 citations to herself or himself when computing her or his h -index, then these 60 citations will be redundantly counted three times on these authors’ separate webpages (e.g., scholar.google.com). This generates totally 180 citation counts by these three authors, thus inappropriately inflating their research productivity and impact from one publication.

Here is an example from Google Scholar Footnote 1 : The publication “Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)” had 10,477 citations as of December 18, 2021. This publication has 2931 authors. Footnote 2 If Google Scholar would list this publication’s 10,477 citations on the webpage of each of those 2931 authors, then each author would have over 10,000 citations on Google Scholar, and Google Scholar would redundantly generate enormous 30,708,087 citation counts in total from this publication to drastically exaggerate research productivity in the research community.

Problem #3–creating unfairness in evaluating research contributions. Each coauthor makes a partial contribution to a multiauthored publication. Because the h -index does not take into account the number of authors in publications, the h -index is computed by ignoring the difference between partial contributions in multiauthored publications and full contributions in single-authored publications, thus creating unfairness in assessing research contributions.

Problem #4–driving the unethical behavior of gift authorship. The h -index has been used for decision-making on appointments, promotion and tenure, etc. Its popularity and importance may drive some people to unethically increase their h -index through gift authorship. Because the h -index does not take the number of authors in each publication into account, some people may add each other’s names to the author lists of publications, in which they have no or little contributions, to unethically boost their h -index.

Solution: taking the number of authors in each publication into account

Although many variants of the h -index have been proposed (Alonso et al., 2009 ; Batista et al., 2006 ; Hirsch, 2019 ; Schreiber, 2008a , b ; Schubert & Schubert, 2019 ; Todeschini & Baccini, 2016 ), the h -index is still widely used for two reasons: it is easy to understand, compute, and interpret by almost all users to evaluate their research productivity and impact; it can be used across different disciplines, different types of publications, etc.

Assessing the research productivity and impact of individual authors more accurately

Among the proposed variants of the h -index, “the fractional h -index” has taken into account the number of authors in publications by “giving an author of an m -authored paper only a credit of \(\frac{c}{m}\) if the paper received c citations” (Egghe, 2008 ). This paper renames “the fractional h -index” to “the h i -index”; one reason is that although a fractional number of citations that each multiauthored publication has received are used to compute each author’s h i -index, the subscript “ i ” is used to emphasize the individual contributions in publications that each author should be accredited. Note that this paper does not propose any new variant of the h -index, but attempts to use the h i -index (i.e., the fractional h -index) to address the aforementioned four problems.

Note that the h i -index is different from the h I -index (Batista et al., 2006 ), the h m -index (Schreiber, 2008a , b ), and the h α index (Hirsch, 2019 ). The h I -index is obtained by dividing “ h by the mean number of researchers in the h publications” (Batista et al., 2006 ); the h I -index “disfavours people with some papers with a large number of co-authors” (Schreiber, 2008a ). The h m -index is determined by comparing “an effective rank” with the number of citations that publications have received (Schreiber, 2008a , b ); it seems more difficult for users (especially non-technical users) to interpret their research productivity and impact by using “an effective rank” than by directly using the number of citations that publications have received. The h α index is proposed as “a measure of the scientific production of a scientist that counts only those papers where the scientist is the leading author”, with an assumption that “the coauthor with the highest h -index is the most likely” leading author in a multiauthored publication (Hirsch, 2019 ); in reality, however, this assumption is questionable for many publications.

To discuss how the h i -index can address the aforementioned four problems, it is necessary to first explain how it works:

The h i -index is used to assess the research productivity and impact of individual authors. For an author who has published k publications in total, the author’s h i -index is defined as the maximum value of n such that the author has n publications, each of which has \(\frac{{c_{j} }}{{m_{j} }} \ge n\) , where the j th publication has m j authors and has received c j citations ( c j  ≥ 1, m j  ≥ 1, 1 ≤  j  ≤  k , 1 ≤  n  ≤  k ), or is 0 if each publication has \(\frac{{c_{j} }}{{m_{j} }}\)  < 1 ( c j  ≥ 0, m j  ≥ 1, 1 ≤  j  ≤  k ).

When computing the h i -index, it is recommended that if the percentages of contributions from the authors to a publication are known, then these percentages should be used to distribute the number of citations that the publication has received among the authors (Tscharntke et al., 2007 ); otherwise, the computation of the h i -index assumes equal contributions from the authors by default.

Mathematically, suppose that an author has k publications in total, and these k publications have m 1 , m 2 , …, m k ( m j ≥ 1, 1 ≤  j  ≤  k ) authors and have received c 1 , c 2 , …, c k ( c j ≥ 0, 1 ≤  j  ≤  k ) citations, respectively;

for each publication, let f be the function that corresponds to the number of citations per author, i.e., \(f(j) = \frac{{c_{j} }}{{m_{j} }}\) (1 ≤  j  ≤  k );

for k publications, if the values of \(f(j) = \frac{{c_{j} }}{{m_{j} }}\) (1 ≤  j  ≤  k ) are ordered in descending order (i.e., the highest value f (1) in the 1st position and the lowest value f ( k ) in the k th position), then the h i -index is computed as follows:

h i -index ( f ) =  \(\left\{ {\begin{array}{*{20}l} {\max \{ j \in {\mathbb{N}}: \, 1 \le j \le k, \, \left\lfloor {f(j)} \right\rfloor \ge j\} \, if \, f(1) \ge 1} \hfill \\ {0 \, if \, f(1) < 1} \hfill \\ \end{array} } \right.\) , where \(\left\lfloor \cdot \right\rfloor\) is the floor function.

As an illustrative example to compare the h -index and the h i -index, Table 1 shows the number of citations ( c j ) and the number of authors ( m j , in parentheses) of an author’s 15 publications (i.e., k  = 15). According to Table 1 , this author’s h -index = 9 based on the publications highlighted in bold. Next, Table 2 calculates the division \(f(j) = \frac{{c_{j} }}{{m_{j} }}\) for each publication. Then, Table 3 reorders the values of \(f(j)\) in Table 2 from high to low, along with the corresponding publications. According to Table 3 , this author’s h i -index = 7 based on the publications highlighted in bold.

Here are two insightful observations from this example. First , publication #11 does not contribute to the h -index = 9 in Table 1 , but it contributes to the h i -index = 7 in Table 3 . It is a single-authored publication. Because #11’s all citations are accredited to this single author’s intellectual contribution, it makes sense that #11 boosts this author’s individual h i -index.

Second , publications #4 and #5 contribute to the h -index = 9 in Table 1 , but they do not contribute to the h i -index = 7 in Table 3 . Although #4’s 37 citations and #5’s 34 citations are higher than most of the other publications in Table 1 , these two publications have the highest numbers of authors among all publications. Having a relatively large number of coauthors probably implies that this author’s contributions in these two publications are relatively small, and thus it makes sense that #4 and #5 do not contribute to increasing this author’s individual h i -index in Table 3 .

Solving the four problems

The aforementioned four problems can be effectively addressed by using the h i -index: The h i -index prevents each author from taking full credit for a multiauthored publication’s all contributions (Problem #1). The h i -index eliminates inflation in counting citations, because it ensures that the portions of a publication’s received citations distributed among its authors will add up to its total number of received citations (Problem #2). By taking a publication’s all authors into account when assessing their contributions to the publication, the h i -index promotes fairness in assessing the research contributions of authors (Problem #3).

To discuss how the h i -index addresses Problem #4, assume that one more person was added to Publication #7 in Table 1 through gift authorship; that is, it had 4 authors and received 25 citations, yielding \(\frac{{c_{7} }}{{m_{7} }} = \frac{25}{4} = 6.25\) . This change does not affect the h -index in Table 1 , but reduces the h i -index from 7 to 6 in Table 3 . In general, adding more people to a publication’s author list through gift authorship will slow down this publication’s potential contribution to each author’s h i -index. The h i -index can make it difficult to “inflate results with coauthorship of documents for reasons other than good scientific performance” (Vieira & Gomes, 2011 ). Due to this effect, the use of the h i -index will discourage authors from adding people with no or little research contributions to their publications, and thus can effectively curb the unethical practice of gift authorship.

From the h -index to the h i -index

Potential impact and causes.

To study how the change from the h -index to the h i -index may potentially impact authors in different fields, this paper compares the h -index and the h i -index of 12 Nobel laureates in four scientific fields. As shown in Table 4 , the citation data of three Nobel laureates in each field are obtained from the Google Scholar webpages.

For each author in Table 4 , (1) =  \(\sum\nolimits_{j = 1}^{k} {c_{j} }\) , (2) =  \(\sum\nolimits_{j = 1}^{k} {\frac{{c_{j} }}{{m_{j} }}}\) , (3) =  \(\frac{{\sum\nolimits_{j = 1}^{k} {\frac{{c_{j} }}{{m_{j} }}} }}{{\sum\nolimits_{j = 1}^{k} {c_{j} } }} \times 100\%\) , (6) =  \(\frac{{h - {\text{index }} - \, h_{i} - {\text{index}}}}{{h - {\text{index}}}} \times 100\%\) , (7) =   \(\frac{{\sum\nolimits_{j = 1}^{k} {m_{j} } }}{k}\) , and (8) =  \(\sum\nolimits_{j = 1}^{k} {c_{j} m_{j} }\) , where the author has k cited publications, and the j th publication has m j authors and has received c j citations ( c j  ≥ 1, m j  ≥ 1, 1 ≤  j  ≤  k ).

Column (8) in Table 4 shows that if the citations in column (1) would be redundantly counted for each author listed in these publications, then Google Scholar would generate much higher total citation counts for all authors. Such huge inflation in counting citations may create misleading impressions of research productivity and impact in the research community.

Based on the data in Table 4 , Fig.  1 shows that for these four scientific fields, the authors in Economic Sciences (i.e., E1, E2, and E3) generally have lower average numbers of authors per cited publication; the authors in Physiology or Medicine (i.e., M1, M2, and M3) generally have higher average numbers of authors per cited publication; however, P2 has the highest average number of authors per cited publication. Figure  1 reveals that different fields, as well as different research areas within the same field (e.g., physics), may have different practices of research collaboration and publication.

The relationship between Table 4 ’s column (6) (in blue) and columns (3) (in green) and (7) (in red)

Although Fig.  1 does not show a simple linear relationship between the blue bars and the red line or the green line, it shows that in general, when the average number of authors per cited publication becomes smaller, or when the percentage of an author’s fractional number of citations becomes larger, the author’s percentage decrease from the h -index to the h i -index becomes smaller.

Based on the data in Table 4 , Table 5 shows the rankings of 12 authors when the h -index is used; Table 6 shows how their rankings change when the h i -index is used instead of the h -index.

There are a few observations from the analysis of these 12 authors in four research fields. First , the rankings of the authors from different fields are all mixed in both Table 5 and Table 6 ; no field is ranked definitely higher or lower than all other fields based on the h -index or the h i -index. Second , when the h i -index is used instead of the h -index, the rankings of all three authors in Economic Sciences are increased (see Table 6 ); this is probably because these three authors have lower average numbers of authors per cited publication than the authors in the other three fields (see Fig.  1 ). Lastly , when the h i -index is used instead of the h -index (see Table 6 ), for each field other than Economic Sciences, some authors’ rankings are increased while some authors’ rankings are decreased; the rankings of M1 and P1 remain unchanged. These observations reveal that changing from the h -index to the h i -index may have different impacts on the rankings of authors in different fields or in different research areas within the same field.

Determining the percentages of partial contributions of coauthors

To calculate an author’s h i -index, it is necessary to determine the author’s percentage of contributions in each multiauthored publication. This paper considers the following two methods:

The first method is that the authors disclose the percentages of their respective contributions in a multiauthored publication. Because different fields may have different practices of research collaboration and publication, it should be the authors who decide their publication’s author list. In general, any individuals who have contributed significantly to a publication should be individually named in the author list. When the authors decide the author list and the order of their names, they typically have some sense about their respective contributions. It is thus possible to estimate such sense into certain percentages of contributions, which sum to 100% for each publication.

The second method is to assume equal contributions from coauthors. When the authors do not disclose the percentages of their respective contributions in a multiauthored publication, this method is desirable for a few reasons: First , because different fields may have different practices of determining the author list, the contributions of authors, the order of authors, etc., this second method practically simplifies and standardizes the implementation of the h i -index across all fields. Second , this method does not force the authors to fight over agreeing on the percentages of their respective contributions in a multiauthored publication, thus encouraging productive research collaboration. Lastly , a prior study showed that for overcoming the h -index’s problem of ignoring the number of authors in each publication, the improvement of the authorship-weighted methods (e.g., first-author-emphasis, corresponding-author-emphasis) compared to the equal-contribution method “is not as high as one would expect” (Vavryčuk, 2018 ). It is also worth mentioning that while the authorship-weighted methods “may be very useful as applied to a particular field or discipline, they cannot be used across the board because of the very different practices in different disciplines regarding order of authors, significance of authorship position in the author’s list, etc.” (Hirsch, 2019 ).

For calculating the h i -index, this paper recommends that if the authors disclose the percentages of their respective contributions in a multiauthored publication, then these percentages should be used for allocating the publication’s received citations among its authors; if the authors do not disclose the percentages of their respective contributions in a publication, then the second method can be used. The second method achieves a good balance of overcoming the h -index’s problem of ignoring the number of authors in each publication, making the h i -index implementable across different fields, encouraging productive research collaboration among coauthors, and keeping it easy for authors to interpret their research productivity and impact in a straightforward way based on the number of citations that each publication has received.

Discussion and conclusion

This paper revealed that because the h -index does not take into account the number of authors in each publication, four major problems exist when the h -index is used to assess the research productivity and impact of authors: individually taking full credit for a multiauthored publication’s all contributions, creating inflation in counting citations, creating unfairness in evaluating research contributions, and driving the unethical behavior of gift authorship. This paper showed that the h i -index (i.e., the fractional h -index), which distributes each publication’s received citations among its authors, can help solve these four problems effectively.

The h i -index has several advantages. First , the h i -index assesses each author’s research productivity and impact more accurately and fairly than the h -index. Second , like the original h -index, the h i -index is still easy to understand, compute, and interpret by almost all users (including non-technical users) in comparison with many other variants of the h -index such as the h I -index and the h m -index. Lastly , the h i -index can be used across different disciplines, different types of publications, etc.

This paper used the Google Scholar data of 12 Nobel laureates in four scientific fields to show what happens when the h i -index is used instead of the h -index. These examples demonstrated that the existing h -index drastically exaggerates research productivity and impact. In addition, these examples showed that the percentage decreases from the h -index to the h i -index are generally smaller for the authors whose average number of authors per publication is smaller (or whose portions of contributions to publications are larger). This finding provides a useful implication that the use of the h i -index can potentially motivate more effort to make research contributions.

Although software has been developed for authors to install and compute their own h i -index, such as Publish or Perish (Harzing 2021 ), the h i -index (i.e., the fractional h -index) is still not widely used. This is probably because nowadays, most authors rely on websites where they can find their h -index instantly. Therefore, this paper recommends that websites (such as scholar.google.com and researchgate.net) should add the h i -index for the sake of building a fairer and more ethical research community, assessing each author’s research productivity and impact more accurately, and encouraging more contributions to research and publication.

Change history

25 february 2023.

A Correction to this paper has been published: https://doi.org/10.1007/s11192-023-04665-x

14 July 2022

A Correction to this paper has been published: https://doi.org/10.1007/s11192-022-04455-x

https://scholar.google.com/citations?view_op=view_citation&hl=en&user=fX-_IToAAAAJ&alert_preview_top_rm=2&authuser=1&citation_for_view=fX-_IToAAAAJ:c1e4I3QdEKYC (accessed December 18, 2021).

https://www.tandfonline.com/doi/full/10.1080/15548627.2020.1797280# (accessed December 18, 2021).

Alonso, S., Cabrerizo, F. J., Herrera-Viedma, E., & Herrera, F. (2009). h-index: A review focused in its variants, computation and standardization for different scientific fields. Journal of Informetrics, 3 (4), 273–289. https://doi.org/10.1016/j.joi.2009.04.001

Article   Google Scholar  

Batista, P. D., Campiteli, M. G., & Kinouchi, O. (2006). Is it possible to compare researchers with different scientific interests? Scientometrics, 68 (1), 179–189. https://doi.org/10.1007/s11192-006-0090-4

Egghe, L. (2008). Mathematical theory of the h- and g-index in case of fractional counting of authorship. Journal of the American Society for Information Science and Technology, 59 (10), 1608–1616. https://doi.org/10.1002/asi.20845

Harzing, AW (2021) Publish or Perish . https://harzing.com/resources/publish-or-perish . Downloaded July 6, 2021.

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

Article   MATH   Google Scholar  

Hirsch, J. E. (2019). hα: An index to quantify an individual’s scientific leadership. Scientometrics, 118 (2), 673–686. https://doi.org/10.1007/s11192-018-2994-1

Schreiber, M. (2008a). A modification of the h-index: The hm-index accounts for multi-authored manuscripts. Journal of Informetrics, 2 (3), 211–216. https://doi.org/10.1016/j.joi.2008.05.001

Schreiber, M. (2008b). To share the fame in a fair way, hm modifies h for multi-authored manuscripts. New Journal of Physics, 10 (4), 040201. https://doi.org/10.1088/1367-2630/10/4/040201

Schubert, A., & Schubert, G. (2019). All along the h-index-related literature: a guided tour. In W. Glänzel, H. F. Moed, U. Schmoch, & M. Thelwall (Eds.), Springer handbook of science and technology indicators (pp. 301–334). Springer. https://doi.org/10.1007/978-3-030-02511-3_12

Chapter   Google Scholar  

Todeschini, R., & Baccini, A. (2016). Handbook of bibliometric indicators: Quantitative tools for studying and evaluating research. Wiley-VCH . https://doi.org/10.1002/9783527681969

Tscharntke, T., Hochberg, M. E., Rand, T. A., Resh, V. H., & Krauss, J. (2007). Author sequence and credit for contributions in multiauthored publications. PLoS Biology, 5 (1), e18. https://doi.org/10.1371/journal.pbio.0050018

Vavryčuk, V. (2018). Fair ranking of researchers and research teams. PLoS ONE, 13 (4), e0195509. https://doi.org/10.1371/journal.pone.0195509

Vieira, E. S., & Gomes, J. A. N. F. (2011). An impact indicator for researchers. Scientometrics, 89 (2), 607–629. https://doi.org/10.1007/s11192-011-0464-0

Download references

Author information

Authors and affiliations.

Willamette University, 900 State Street, Salem, OR, 97301, USA

Henry H. Bi

You can also search for this author in PubMed   Google Scholar

Corresponding author

Correspondence to Henry H. Bi .

Additional information

The original online version of this article was revised due to a retrospective Open Access order.

The original online version of this article was revised: In the original version of the article there were minor corrections in Table 4, text sentence corrections and references.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ .

Reprints and permissions

About this article

Bi, H.H. Four problems of the h -index for assessing the research productivity and impact of individual authors. Scientometrics 128 , 2677–2691 (2023). https://doi.org/10.1007/s11192-022-04323-8

Download citation

Received : 14 September 2021

Accepted : 21 February 2022

Published : 12 March 2022

Issue Date : May 2023

DOI : https://doi.org/10.1007/s11192-022-04323-8

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Productivity
• Publication
• Find a journal
• Publish with us
• Track your research

Katie Schulman

Improve your h-index with these 10 practical strategies.

I recently came across an interesting discussion on ResearchGate 1 about how to get cited more. Since it’s an important measure for academics – often in the form of the so-called h-index – I looked at a few sites to learn about practical strategies.

Being cited is one way of showing the impact of your research. It’s also not easy, as there is an enormous amount of papers being published each year. Moreover, there are language issues. For instance, if I write in German, I make it easier for students to read my paper and be cited by my German speaking colleagues (not all of them might be comfortable in English). On the other hand, publishing in English means people from many countries can read – and cite – my work.

Getting cited is a slow process. Publications in peer-reviewed papers can take a long time, which means it takes a while to get citations.

The h-index

One popular measure for citations is the h-index. The h-index combines how many papers you publish and how often these papers got cited into a single metric 2 . The h-index is available for instance on Google Scholar. There are also apps, like ‘Publish or Perish’.

Currently, Google Scholar shows my h-index as 6, with 139 citations.

What is a good h-index? That seems to vary widely by field 3 . For instance, Holosko & Barner 4 showed that assistant professors in social work had an average h-index of 5, associate professors of 8 and full professors of 16. In psychology, these numbers were 6, 12 and 23. Albion 5 showed that in education, associate professors had an average h-index of 6.2 and professors of 10.6. Researchers at the London School of Economics and Political Science (LSE) 6 found that lecturers in geography had an average h-index of 3.73, senior lecturers of 5.75 and professors of 6.50. So, mine isn’t that bad : ) .

Ways for improving the h-index

Still, there’s still room for improvement. On the web, there’s a lot of advice on how to improve your h-index.

Make your future publications citation-friendly

A lot of the strategies seem to focus on things that you can do before submitting the paper for publication.

• Choose the right venue : The LSE paper 6 also found that it matters in what type of venue you publish. For geography, academic articles got way more cites than conference papers. Others suggest that accessibility plays a role. Online, free-of-charge papers get more citations than a book that needs to be ordered from the library 9 , 13 , 14 . Peer-reviewed papers (especially in high-impact journals) are not just better regarded, but also might help boost your h-index 13 . Publishing in venues of different disciplines reaches a larger audience 13 . However, if there’s a venue most people in your field read, try to get in there 14
• Check the attribution: Use ORCID or a similar service to make sure all the papers get attributed to you 7 , 13 , 14 . Some say you should have a consistent version of the name for all publications 13, 14 . However, that doesn’t work if you choose to take your partners name upon marriage, for instance – something I’m looking forward to.
• Consider adding citation-friendly types of publications to your list: Publishing the results of your projects is important, of course. However, review papers and how-to (methodology) papers get cited more widely than research articles 9 , 1 , 13, 14 . So in-between those results-focused papers, consider doing a review paper. It’s especially beneficial to be the first to do a review in a particular area 14 .
• Make your paper useful: The more useful to others, the more likely they are to cite it 9 . This can also mean framing your research in relation to what’s “hot” at the moment in your field 13.
• Make your paper SEO friendly: This can include making sure keywords (that people actually search for) are in the title, body and abstract; having proper meta-data and including the article in places Google crawls and accepts as authoritative 13 ,14  such as ResearchGate, Academia and your institution’s repository.
• Citing yourself is obvious – a new paper can be one of the ways to get the word out about your previous research and get self-cites. But please, don’t overdo it by including those that are not relevant – despite what this Indonesian example of extreme self-citation on academia claims 15 .
• Ebrahim, Gholizadeh and Lugmayr 13 summarize research that shows “[…] a ridiculously strong relationship between the number of citations a paper receives and the number of its references […]”. So make sure to include a strong literature review.
• According to a study by Hudson 8 , titles should be short. However, Jamali & Nikzad found no correlation, and Habibzadeh & Yadollahie showed more favorable results for longer titles 12 . Ebrahim, Gholizadeh & Lugmayr conclude that optimal title length depends on the field 13 . In a study by ResearchTrends, “titles between 31 to 40 characters were cited the most” 12 .
• Hudson also found that you shouldn’t use questions 8 . A study by Tse & Zhou suggests you should not use hyphens 8 . Jamali & Nikzad found colons and question marks not to work well 12 , 13, 14 . Paiva et al. say no colon, hyphen or question mark 13 . In contrast, Griffith says that colons are good 14 . The ResearchTrends study found that “the ten most cited papers […] did not contain any punctuation at all” 1 2 .
• In another study, a team from Italy found that you shouldn’t put “country names in the title, abstract or keywords” 8. Paiva et al’s also advise against country names in the title 13.
• There’s no need for trying to be funny or play on words. A study by Sagi & Yechiam found that “articles with highly amusing titles […] received fewer citations” 1 2 .
• Think about the authors: In many situations, you don’t have a choice who the authors are. For instance, if you’re working on a certain project together, then that’s most likely who the authors will be. However, Hudson found that having too many authors isn’t good for citations 8 , while Wuchty et al. found “that team-authored articles typically produce more frequently cited research than individuals” 13 .Research shows that having co-authors from different countries is good for attracting citations 13 ,14 . Some especially suggest that super-well known (and cited) co-authors can boost the citations for your paper 1, 14 – so if you can get a Nobel laureate to be co-author on your paper, go for it 13 …

Get more citations for already published work

But what if you have, like I, worked for a couple of years and already have a list of publications? Less strategies seem to deal with how to increase citations for past work. Two ways I found are:

• Get known: Since well-known co-authors can boost your h-index, one could argue that becoming more well-known yourself would also boost your h-index. This can include e.g. conference presentations (and schmoozing with colleagues), social media, blogging and ‘branding yourself’ 13,  7 .
• Get your work out there: This can mean spreading the word about your work e.g. on blogs and your website; social media such as ResearchGate, Academia and Linkedin, or even mass media 1, 13, 14 . You can even send out information about your work to some key people 13 ,14 . . Learn about marketing and apply that to your work 13 . Others would likely disagree about the social media aspect. For instance, Cal Newport often argues against using social media 10 , and instead advocates for doing ‘deep work’ which leads to better quality work 11 . What research does see as important is making the papers available: several studies have found a positive impact of self-archiving 13 . So keep your lists up-to date and easy to find online 13 . This can even mean including your work into relevant Wikipedia articles – or writing a Wikipedia article on your topic yourself 13 ,14 .

Reviewing my existing strategy

Looking through my publication list , one of the things I noticed are the titles. I do have a book chapter on GIS education that has Germany in the title .  There are two papers with question marks: one I published with some of my students on how much of geography education research actually ends up in classroom practice and my article on Public Judaism. Several titles have other punctuation: “.”, “–” and “:”. In general, many of the titles are quite long.

According to Google Scholar, my best-performing paper is a r eview paper on GIS education that I’ve authored with international, well-known colleagues.

In terms of ‘getting the word out there’, I have written on Wikipedia before, but haven’t used that systematically. I also notice that while I keep the publication list on my website always up to date, there’s often a lag till I’ve updated my profiles on ResearchGate , Academia , GoogleScholar etc.

Planning to improve my h-index

I have several publications to write in the upcoming semester – among other things about the #TCDTE project   and teacher conceptions . Based on the 10 strategies, I might have to consider writing a review style paper too.

I’m curious to see how much applying the 10 strategies will improve my h-index in the coming months.

Related Posts

Lessons learned from the online presence of 16 geography education professors, about the author.

Katie Viehrig

Thanks for this very interesting review. I’ll paste it to my networks, especially directed to young researchers, but not only… Gil Mahé from IRD Montpellier France

Thanks so much! Glad you find it useful : )

Save my name, email, and website in this browser for the next time I comment.

Privacy Overview

Research Metrics

• Scholarly Profiles
• Journal-level Metrics

Introduction: Author-Level Metrics

• Web of Science

Google Scholar

Controversial tools, academia.edu, researchgate.

• Book-level Metrics
• Article-level Metrics
• Definitions
• Benefits and Impact
• Types of Open Access Publishing
• Evaluating Open Access Journals
• Experts @ Syracuse This link opens in a new window
• Research Metrics Challenge This link opens in a new window
• CV/Resume Citing: Conferences Cancelled or Changed
• ORCID This link opens in a new window
• Responsible Research Assessment
• Additional Resources

Author-level metrics measure the impact of the scholarly output of a single researcher. Author-level metrics are designed to help researchers assess the cumulative impact of their work, rather than the impact of a single publication. All author-level metrics are derived from article-level metrics: they aggregate or summarize the impact of an author's publications.

*Resources that are controversial. Please refer to the "Controversial Tools" tab.

Frequently-used Metrics

h-index: measures the cumulative impact of a researcher's output by looking at the number of citations a work has received

i10-index: created by Google Scholar, it measures the number of publications with at least 10 citations

g-index: aims to improve on the h-index by giving more weight to highly-cited articles

e-index: The aim of the e-index is to differentiate between scientists with similar h-indices but different citation patterns

For more information on these and additional metric options, visit  Publish or Perish  and  Metrics Toolkit .

Limitations

As a "general rule of thumb:

• If an academic shows good citation metrics, it is very likely that he or she has made a significant impact on the field.

"However, the reverse is not necessarily true. If an academic shows weak citation metrics, this may be caused by a lack of impact on the field, but also by one or more of the following:

• Working in a small or newly developing field (therefore generating fewer citations in total)
• Publishing in a language other than English (LOTE - effectively also restricting the citation field);
• Publishing mainly (in) books."

Source: Anne-Wil Harzing,  Publish or Perish

Note on Citation Analysis

Citation analysis is a quantifiable measure of academic output. Users need to be aware of the limitations and incongruities of citation metrics. Library subscription databases and Google Scholar do not correct errors in citing papers. This means that one paper may be cited many different ways and appear as separate entries in these tools. Also, author and institutional naming inconsistencies complicate these analyses. Comparisons between these tools should be avoided. The databases use different sources to generate data and some are more comprehensive than others.  

The Author Citation Report in Web of Science will generate an h-index, total number of publications, sum of times cited, and citing articles in both a text and graphical format. The report also includes a breakdown of each publication, cites per year, and average citations of that publication per year. Caveat: this data is extracted from Web of Science publications, so it is recommended to also use one of the other author-level metrics tools for a more comprehensive view of an author's work.

Searching an Author in Web of Science:

• start with the "Author Search," adding name and initial(s) as indicated, then add "Research Domain" (if relevant) and select the organization
• at the results page, click on "Create Citation Report"
• the report can be exported by saving to an Excel or text file

Adapted with permission from the  University of Oklahoma Research Impact Metrics research guide .

Your Google Scholar profile will include a list of the articles you have entered, with "cited by" links for each of them. Google Scholar will display a graph of your citation activity and calculate your total number of citations, h-index, and i10-index. The profile also includes a "recent" version of those three metrics, based on activity in the last five years.

Creating Your Profile in Google Scholar:

click "My Profile" at the top and either login to your Google account (or create a new one)

you will be prompted to enter some brief biographical information

add your articles and decide how to handle updates

Note that your profile is private by default. You can opt to make it public on your profile page.

Mendeley is a reference manager and academic social network. Creating a profile allows researchers to interact with colleagues and track some metrics on the use of their work. Please note that although Mendeley was purchased by Elsevier in 2013, it uses Scopus to generate its metrics and include non-Elsevier materials.

Creating Your Mendeley Profile:

• click "Create a free account" and enter some basic information
• after your profile is created, you can add your research interests, biography, and publications
• you can view your publication count, citations, views, and readers by clicking "Stats" in the top navigation bar

Use Publons (available within Web of Science) to track your publications, citation metrics, peer reviews, and journal editing work in a single profile. Your publications will be imported from Web of Science, ORCID, or your citation manager (e.g. EndNote or Mendeley), along with citation metrics from the Web of Science Core Collection. Download a record summarizing your scholarly impact as an author, editor and peer reviewer.

Creating Your Publons Profile:

• register with your email address, ORCID, Google account, LinkedIn, or WeChat

Controversial Tools: Academia.edu and ResearchGate

Academia.edu and ResearchGate both seem attractive to scholars, but they also have their share of disadvantages and downsides. We think it is especially important to place these two sites into context and preface them with important considerations.

Consideration #1: You Are Not the Customer

Similar to many other academic social networks, you are not the customer when you interact with these companies, even though you may feel like one. Instead, you are the product that these services seek to monetize and/or “offer up” to advertisers. We do not fault businesses for making money; that is the imperative for them to exist. But we also see Academia.edu and ResearchGate as an extension of those who monetize what many scholars believe should be freely shared. Importantly, if these companies are bought, sold, or go out of business, what would happen to the content you have placed there? This is one reason why it is advisable to first upload items you want to share – articles, preprints, postprints, conference posters, proceedings, slide decks, lesson plans, etc. – to SURFACE, SU’s institutional repository where you can deposit your work. The items in SURFACE are indexed by Google and Google Scholar, so they are searchable, findable, and downloadable by researchers around the world. SU Libraries maintains the platform, the content, and the links. Most importantly, maintaining and preserving content is one of the core missions of SU Libraries. We are not going out of business, so your content on SURFACE will not go away either.

Consideration #2: You Might Be Breaking the Law

Another consideration with these particular services is the legality of uploading your work to these platforms. Most publishers require authors to sign a publication agreement/copyright transfer prior to a manuscript being published, which outlines what you can/cannot do with your own work in the future. Uploading your work –  especially a publisher’s pdf  – to a site such as Academia.edu or ResearchGate may be a violation of the terms of the publishing agreement, whereas uploading it to an institutional repository may not be (or can be negotiated not to be). Several years ago,  a major academic publisher  actively went after Academia.edu, requiring them to take down all of the publisher’s content that had been illegally uploaded, much to the surprise and dismay of the authors. And Academia.edu  is not the only target . In 2018, ResearchGate was set to take down  nearly 7 million articles  or about 40% of their content.

Consideration #3: Understand the Privacy Implications

Finally, some of these sites’ tactics are troubling from the standpoint of privacy and intellectual freedom. Personally and professionally, many find it distressing that a private company, which does not adhere to the same  professional ethics  as librarians and other scholars do, collects information about who is reading what. Academia.edu, in particular, then offers to share that information with you if you subscribe to their “premium service.” And while their analytics dashboard does not reveal readers’ names, it may provide enough information for you to know exactly who read your work. You may decide not to pay for Academia.edu’s premium service, but even so – what you view and download will still be tracked. This may not be troubling to you (the “I’m not doing anything wrong, so I don’t care” argument), but we think it sets a bad precedent. What about tracking researchers who study terrorism? Or whistleblowing? Or even climate change? How might people at these academic social media companies create profiles and make judgments about you based on what you are reading? And what will they do with the information they collect, especially if asked for it by government entities?

Additional Readings and Resources:

• A Social Networking Site is Not an Open Access Repository  by Katie Fortney and Justin Gonder
• I Have a Lot of Questions: RG, ELS, SN, STM, and CRS  by Lisa Janicke Hinchliffe
• Dear Scholars, Delete Your Account At Academia.Edu  by Sarah Bond
• Academia, Not Edu  by Kathleen Fitzpatrick
• Reading, Privacy, and Scholarly Networks  by Kathleen Fitzpatrick
• Upon Leaving Academia.edu  by G. Geltner
• Should You #DeleteAcademiaEdu  by Paolo Mangiafico
• Should This Be the Last Thing You Read on Academia.edu?  by Gary Hall (downloads as a .pdf)

Adapted with permission from the University of Oklahoma Research Impact Metrics research guide.

*Controversial Tool (go to the Controversial Tools tab for more information)

Academia.edu (like ResearchGate) is designed to be an online research community with a social network component. You can upload papers and follow other scholars. Before uploading any of your papers, please ensure that you have permission from the publisher to do so. This falls under "Green" Open Access for author self-archiving. Remember your audience will likely run into a paywall in accessing this content. Additionally, Academia.edu does not offer traditional metrics but does show document and page views.  Please note that, although the site has an .edu domain, it is not associated with an educational institution.

Creating Your Academia.edu Profile:

• sign up using Google, Facebook, or an email address
• after entering your login information, you will be prompted to designate your status as researcher (faculty, graduate student, post-doc, etc.)
• you will then be prompted with suggestions of other researchers to follow
• after your profile has been created, you can add your publications and a biography

ResearchGate (Iike Academia.edu) is designed to be an online research community and functions as a social network for researchers. Users can share updates about their research and full papers, and they can follow others to receive updates about their works. In addition to reads, citation counts, profile views, and h-index, ResearchGate has its own metric called RG score. As it is created by a propriety algorithm, it is not clear how this number is generated; therefore, it should be used only cautiously.

Creating Your ResearchGate Profile:

• click "Join for Free" and select "Academic"
• you can then confirm your authorship
• when selecting your publications, you will see a check box selected by default that will automatically send your coauthors an invitation to join Research Gate, so be sure to un-check this box if you do not want to send these emails
• add research interests and skills
• ResearchGate will then suggest that you follow others from your institution
• << Previous: Journal-level Metrics
• Next: Book-level Metrics >>
• Last Updated: Jan 19, 2024 9:44 AM
• URL: https://researchguides.library.syr.edu/researchmetrics
• Print This Page

• Interlibrary Loan

Ask an Expert

Ask an expert about access to resources, publishing, grants, and more.

MD Anderson faculty and staff can also request a one-on-one consultation with a librarian or scientific editor.

• Library Calendar

Log in to the Library's remote access system using your MyID account.

• UT MD Anderson Cancer Center
• Ask the Research Medical Library

Q. What is an h-index? How do I find the h-index for a particular author?

• 3 altmetrics
• 1 BioRender
• 11 cited references
• 8 collections
• 5 Copyright
• 3 data management
• 12 databases
• 1 Editing Services
• 5 full text
• 7 impact factors
• 3 Interlibrary Loan
• 10 journals
• 6 NIH Public Access Policy
• 4 open access
• 1 Other Libraries
• 2 peer review
• 1 plagiarism
• 19 publishing
• 41 reference
• 14 services
• 12 Systematic Reviews

Answered By: Laurissa Gann Last Updated: Mar 27, 2023     Views: 413235

The h-index is a number intended to represent both the productivity and the impact of a particular scientist or scholar, or a group of scientists or scholars (such as a departmental or research group). 

The h-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.  For instance, an h-index of 17 means that the scientist has published at least 17 papers that have each been cited at least 17 times.  If the scientist's 18th most cited publication was cited only 10 times, the h-index would remain at 17.  If the scientist's 18th most cited publication was cited 18 or more times, the h-index would rise to 18.

Part of the purpose of the h-index is to eliminate outlier publications that might give a skewed picture of a scientist's impact.  For instance, if a scientist published one paper many years ago that was cited 9,374 times, but has since only published papers that have been cited 2 or 3 times each, a straight citation count for that scientist could make it seem that his or her long-term career work was very significant.  The h-index, however, would be much lower, signifying that the scientist's overall body of work was not necessarily as significant.

The following resources will calculate an h-index:

Web of Science

Pure (MD Anderson Faculty and Fellows listed)

Keep in mind that different databases will give different values for the h-index.  This is because each database must calculate the value based on the citations it contains.  Since databases cover different publications in different ranges of years, the h-index result will therefore vary.   You should also keep in mind that what is considered a "good" h-index may differ depending on the scientific discipline.  A number that is considered low in one field might be considered quite high in another field.

A note about Google Scholar

Google Scholar usually provides the highest h-index compared to other sources. This is because Google Scholar indexes web pages not organized collections of article citations, like databases. This means Google Scholar:

• Counts all publications, including books
• Counts all versions of a paper it finds, including preprints
• Counts self-citations 
• Counts citations added manually, but not necessarily verified by a publisher or other source

Links & Files

• How do I determine how many times and article was cited?
• Share on Facebook

Was this helpful? Yes 200 No 69

Comments (0)

Chat or Zoom Live with Staff

Text Us: (281) 369-4872

Call Us: +1 (713) 792-2282

View Research Guides

Request an Online Consultation

Related Topics

Reference management. Clean and simple.

How to find your h-index on Google Scholar

How to calculate your h-index using Google Scholar

The name says it all: get more insights using harzing's "publish or perish", can you trust the h-index calculated with google scholar, frequently asked questions about finding your h-index on google scholar, related articles.

Google Scholar is a search engine with a special focus on academic papers and patents. It's limited in functionality compared to the major academic databases Scopus and Web of Science , but it is free, and you will easily know your way around because it is like doing a search on Google.

While Scopus and Web of Science limit their analyses to published journal articles, conference proceedings, and books, Google Scholar uses the entire internet as its source of data. As a result, the h-index reported by Google Scholar tends to be higher than the one found in the other databases.

➡️  What is the h-index?

Google Scholar can automatically calculate your h-index; you just need to set up a profile first. By default, Google Scholar profiles are public - allowing others to find you and see your publications and h-index. However, if you don't want to have such a public web presence, you can un-tick the "make my profile public" box on the final page of setting up your profile.

Once you have set up your profile, the h-index will be displayed in the upper right corner. Besides the classic h-index, Google also reports an i10-index along with the h-index. The i10-index is a simple measurement that shows how many of the author's papers have 10 or more citations.

Google Scholar also has a special author search , where you can look up the author profiles of others. It will, however, only show results for scholars with public profiles, as well as those of historical scientists like Albert Einstein .

Google Scholar's extensive database might list publications that most academics would not include in an h-index analysis. So it might be useful to vet the papers before calculating the h-index. Scopus and Web of Science offer such functionality to some extent, but for Google Scholar it's not possible to do right in your browser. However, there is a free desktop application called Publish or Perish , that allows you to just do that. It's available on Windows, and with some effort, you can also run it on macOS and Linux.

In order to check an author's h-index with Publish or Perish go to "Query > New Google Scholar Profile Query". Enter the scholar's name in the search box and click lookup. A window will open with potential matches. After selecting a scholar, the program will query Google Scholar for citation data and populate a list of papers, and present summary statistics on the right of this list. The list is particularly helpful because it can be used to exclude false positives.

In addition to the standard h-index, Publish or Perish, also calculates Egghe's g-index , along with normalized and annual individual h-indexes. You can read more about how these are calculated in the Publish or Perish manual .

As illustrated in Stephen Hawking's Google Scholar h-index and also noted by others , the h-index in Google Scholar tends to be higher than in Scopus or Web of Science. The main reason for this discrepancy is mainly attributed to the use of different data sources.

While Google Scholar grabs citation information from all over the internet, Scopus and Web of Science restrict their data sources to classic academic sources. Each approach is valid on its own. One could say that Google Scholar's h-index is more up-to-date as it also includes "early citations" from pre-prints before the article is actually published in an academic journal.

Also with the rise of "altmetrics", there is generally a trend to measure the resonance of academic papers outside the strict academic world. However, since Google Scholar's approach is fully automatic and not subject to any review, it can also be manipulated rather easily .

For example, you could upload false scholarly papers that give unsupported citation credit, or add papers to the Google Scholar profile that were not even authored by the person in question. Yes, there is room for improvement, but Google Scholar's h-index is a great free alternative to subscription-based databases.

You can learn how to calculate your h-index using Scopus and Web of Science below:

➡️  How to use Scopus to calculate your h-index

➡️  How to use Web of Science to calculate your h-index

An h-index is a rough summary measure of a researcher’s productivity and impact . Productivity is quantified by the number of papers, and impact by the number of citations the researchers' publications have received.

Even though Scopus needs to crunch millions of citations to find the h-index, the look-up is pretty fast. Read our guide How to calculate your h-index using Scopus for further instructions.

Web of Science is a database that has compiled millions of articles and citations. This data can be used to calculate all sorts of bibliographic metrics including an h-index. Read our guide How to use Web of Science to calculate your h-index for further instructions.

The h-index is not something that needs to be calculated on a daily basis, but it's good to know where you are for several reasons. First, climbing the h-index ladder is something worth celebrating. But more importantly, the h-index is one of the measures funding agencies or the university's hiring committee calculate when you apply for a grant or a position. Given the often huge number of applications, the h-index is calculated in order to rank candidates and apply a pre-filter.

An h-index is calculated as the number of papers with a citation number ≥ h. An h-index of 3 hence means that the author has published at least three articles, of which each has been cited at least three times.

What is the H-index, and Does it Matter?

Listen to one of our scientific editorial team members read this article. Click here to access more audio articles or subscribe.

The h-index is a measure of research performance and is calculated as the highest number of manuscripts from an author (h) that all have at least the same number (h) of citations. The h-index is known to penalize early career researchers and does not take into account the number of authors on a paper. Alternative indexes have been created, including the i-10, h-frac, G-index, and M-number.

How do you measure how good you are as a scientist? How would you compare the impact of two scientists in a field? What if you had to decide which one would get a grant? One method is the h-index, which we will discuss in more detail below. First, we’ll touch on why this is not a simple task.

Measuring scientific performance is more complicated and more critical than it might first seem. Various methods for measurement and comparison have been proposed, but none of them is perfect.

At first, you might think that the method for measuring scientific performance doesn’t concern you—because all you care about is doing the best research you can. However, you should care because these metrics are increasingly used by funding bodies and employers to allocate grants and jobs. So, your perceived scientific performance score could seriously affect your career.

Metrics for Measuring Scientific Performance

What are the metrics involved in measuring scientific performance? The methods that might first spring to mind are:

• Recommendations from peers. At first glance, this is a good idea in principle. However, it is subject to human nature, so personal relationships will inevitably affect perceived performance. Also, if a lesser-known scientist publishes a ground-breaking paper, they would likely get less recognition than if a more eminent colleague published the same paper.
• The number of articles published. A long publication list looks good on your CV, but the number of articles published does not indicate their impact on the field. Having a few publications well-heeded by colleagues in the field (i.e., they are cited often) is better than having a long list of publications cited poorly or not at all.
• The average number of citations per article published. So, if it’s citations we’re interested in, then surely the average number of citations per paper is a better number to look at. Well, not really. The average could be skewed dramatically by one highly cited article, so it does not allow a good comparison of overall performance.

The H-Index

In 2005, Jorge E. Hirsch of UCSD published a paper in PNAS in which he put forward the h-index as a metric for measuring and comparing the overall scientific productivity of individual scientists. [1]

The h-index has been quickly adopted as the metric of choice for many committees and bodies.

How to Calculate An Author’s H-Index

The h-index calculation is pretty simple. You plot the number of papers versus the number of citations you (or someone else) have received, and the h-index is the number of papers at which the 45-degree line (citations=papers, orange) intercepts the curve, as shown in Figure 1 . That is, h equals the number of papers that have received at least h citations. For example, do you have one publication that has been cited at least once? If the answer is yes, then you can go on to your next publication. Have your two publications each been cited at least twice? If yes, then your h-index is at least 2. You can keep going until you get to a “no.”

So, if you have an h-index of 20, you have 20 papers with at least 20 citations. It also means that you are doing pretty well with your science!

What is a Good H-Index?

Hirsch reckons that after 20 years of research, an h-index of 20 is good, 40 is outstanding, and 60 is truly exceptional.

In his paper, Hirsch shows that successful scientists do, indeed, have high h-indices: 84% of Nobel Prize winners in physics, for example, had an h-index of at least 30. Table 1 lists some eminent scientists and their respective h-indexes.

Table 1: H-index scores of some Nobel Laureates (data from Google Scholar collected on September 27, 2023).

Advantages of the H-Index

The advantage of the h-index is that it combines productivity (i.e., number of papers produced) and impact (number of citations) in a single number. So, both productivity and impact are required for a high h-index; neither a few highly cited papers nor a long list of papers with only a handful of (or no!) citations will yield a high h-index.

Limitations of the H-Index

Although having a single number that measures scientific performance is attractive, the h-index is only a rough indicator of scientific performance and should only be considered as such.

Limitations of the h-index include the following:

• It does not take into account the number of authors on a paper. A scientist who is the sole author of a paper with 100 citations should get more credit than one on a similarly cited paper with 10 co-authors.
• It penalizes early-career scientists. Outstanding scientists with only a few publications cannot have a high h-index, even if all of those publications are ground-breaking and highly cited. For example, Albert Einstein would have had an h-index of only 4 or 5 if he had died in early 1906 despite being widely known as an influential physicist at the time.
• Review articles have a greater impact on the h-index than original papers since they are generally cited more often.
• The use of the h-index has now broadened beyond science. However, it’s difficult to compare fields and scientific disciplines directly, so, really, a ‘good’ h-index is impossible to define.

Calculating the H-Index

There are several online resources and h-index calculators for obtaining a scientist’s h-index. The most established are ISI Web of Knowledge, and Scopus, both of which require a subscription (probably via your institution), but there are free options too, one of which is Publish or Perish .

You might get a different value if you check your own (or someone else’s) h-index with each of these resources. Each uses a different database to count the total publications and citations. ISI and Scopus use their own databases, and Publish or Perish uses Google Scholar. Each database has different coverage and will provide varying h-index values. For example, ISI has good coverage of journal publications but poor coverage of conferences, while Scopus covers conferences better but needs better journal coverage pre-1992. [2]

Is the H-index Still Effective?

A paper published in PLoS One in 2021 concluded that while a scientist’s h-index previously correlated well with the number of scientific awards, this is no longer the case. This lack of correlation is partly because of the change in authorship patterns, with the average number of authors per paper increasing. [3]

Are Alternatives to the H-Index Better?

Let’s take a look at some of the alternative measures available.

The H-Frac Index

The authors of the PLoS One paper suggest fractional analogs of the h-index are better suited for the job. [3] Here, the number of authors on a paper is also considered. One such measure is the h-frac, where citation counts are divided by the number of authors. However, this solution could also be manipulated to the detriment of more junior researchers, as minimizing the number of authors on a paper would maximize your h-frac score. This could mean more junior researchers are left off papers where they did contribute, harming their careers. 

The G-Index

This measure looks at the most highly cited articles of an author and is defined as “the largest number n of highly cited articles for which the average number of citations is at least n .” [4] This measure allows highly cited papers to bolster lower cited papers of an author. 

The i-10 Index

Developed by Google Scholar, this index is the number of articles published by an author that have received at least 10 citations. This measure, along with the h-index, is available on Google Scholar.

The m-value was developed to try to balance the scales for early career researchers. It corrects the h-index for time, allowing for easier comparison of researchers with different seniority and career lengths. It is calculated as the h-index divided by the number of years.

The Problem with Measuring Performance

While these numbers can be helpful to give a flavor of a scientist’s performance, they are all flawed. Many are biased towards researchers who publish often and are further into their careers. Many of these indexes can also be manipulated, such as adding extra authors to papers who didn’t contribute.

In reality, it isn’t possible to distill a researcher’s contributions to a single number. They may not have published many papers, but those papers they have published made vital contributions. Or their skills are in training the next round of researchers. When looking at these numbers, we should remember they are just a reflection of one small part of a researcher’s contributions and values and are not the be-all and end-all.

The H-Index Summed Up

The h-index provides a useful metric for scientific performance, but only when viewed in the context of other factors. While other measures are available, including the i-10 index, the G-index, and the h-frac index, these also have limitations. Therefore, when making decisions that are important to you (funding, job, finding a PI), be sure to read through publication lists, talk to other scientists (and students) and peers, and take account of career stage. So, remember that an h-index is only one consideration among many—and you should definitely know your h-index—but it doesn’t define you (or anyone else) as a scientist.

• Hirsch JE. (2005) An index to quantify an individual’s scientific research output . PNAS 102(46):16569–72
• Meho LI, Yang K. (2007) Impact of data sources on citation counts and rankings of LIS faculty: Web of science versus scopus and google scholar . JASIST 58(13):2105–25
• Koltun V, Hafner D. (2021) The h-index is no longer an effective correlate of scientific reputation . PLoS One . 16(6):e0253397
• Wikipedia. g-index . Accessed 25 September 2023

Originally published April 2, 2009. Reviewed and updated October 2023.

It seems doubtful whether all fields of research can be effectively measured in this way. I am a First World War historian. If I want to be cited a lot, I will write about very popular questions (masculinity, identity, space etc at the moment). If I go off into virgin territory and explore, for the first time ever, say, comparative studies of First World War popular music, I will get far fewer citations for a good while, and this may see, a strange reward for asking rarer questions. Whereas asking rare questions, in history, is a key skill (see Keith Thomas for example). This is one of the reasons that scholarly human sciences organizations in France where I live often refuse to use bibliometric indexes of this sort.

I’ve recently proposed a novel index for evaluation of individual researchers that does not depend on the number of publications, accounts for different co-author contributions and age of publications, and scales from 0.0 to 9.9 ( https://f1000research.com/articles/4-884 ). Moreover, it can be calculated with the help of freely available software. Please, share your thoughts on it. Would you use it along with the h-index, or maybe even instead of it, for evaluating your peers, potential collaborators or job applicants? If you’ve tried it on the people you know, do you find the results fair?

Leave a Comment Cancel Reply

You must be logged in to post a comment.

This site uses Akismet to reduce spam. Learn how your comment data is processed .

Forgot your password?

Lost your password? Please enter your email address. You will receive mail with link to set new password.

Back to login