H-index

The h-index is defined as the maximum value of h such that the given author/journal has published at least h papers that have each been cited at least h times.{{Cite news |last=McDonald |first=Kim |date=8 November 2005 |title=Physicist Proposes New Way to Rank Scientific Output |url=http://www.physorg.com/news7971.html |access-date=13 May 2010 |work=PhysOrg}}

File:H-index-en.svgThe h-index is the largest h such that h articles have at least h citations each. For example, if an author has five publications, with 9, 7, 6, 2, and 1 citations (ordered from greatest to least), then the author's h-index is 3, because the author has three publications with 3 or more citations. However, the author does not have four publications with 4 or more citations.

Clearly, an author's h-index can only be as great as their number of publications. For example, an author with only one publication can have a maximum h-index of 1 (if their publication has 1 or more citations). On the other hand, an author with many publications, each with only 1 citation, would also have an h-index of 1.

Formally, if f is the function that corresponds to the number of citations for each publication, we compute the h-index as follows: First we order the values of f from the largest to the lowest value. Then, we look for the last position in which f is greater than or equal to the

position (we call h this position). For example, if we have a researcher with 5 publications A, B, C, D, and E with 10, 8, 5, 4, and 3 citations, respectively, the h-index is equal to 4 because the 4th publication has 4 citations and the 5th has only 3. In contrast, if the same publications have 25, 8, 5, 3, and 3 citations, then the index is 3 (i.e. the 3rd position) because the fourth paper has only 3 citations.

:f(A)=10, f(B)=8, f(C)=5, f(D)=4, f(E)=3　→ h-index=4

:f(A)=25, f(B)=8, f(C)=5, f(D)=3, f(E)=3　→ h-index=3

If we have the function f ordered in decreasing order from the largest

value to the lowest one, we can compute the h-index as follows:

:h-index (f) = $\backslash max\backslash \{i\backslash in\backslash N:\; f(i)\backslash ge\; i\backslash \}$

The Hirsch index is analogous to the Eddington number, an earlier metric used for evaluating cyclists.{{Cite journal |last1=Jeffers |first1=David |last2=Swanson |first2=John |date=November 2005 |title=How high is your E? |url=https://iopscience.iop.org/article/10.1088/2058-7058/18/10/30 |journal=Physics World |volume=18 |issue=10 |page=21 |doi=10.1088/2058-7058/18/10/30 |access-date=2022-09-17}} h-index is also related to Sugeno integral and Ky Fan metric.{{Cite journal |last1=Mesiar |first1=Radko |last2=Gagolewski |first2=Marek |date=December 2016 |title=H-Index and Other Sugeno Integrals: Some Defects and Their Compensation |url=https://ieeexplore.ieee.org/document/7378290 |journal=IEEE Transactions on Fuzzy Systems |volume=24 |issue=6 |pages=1668–1672 |doi=10.1109/TFUZZ.2016.2516579 |issn=1941-0034 |s2cid=1651767}} The h-index serves as an alternative to more traditional journal impact factor metrics in the evaluation of the impact of the work of a particular researcher. Because only the most highly cited articles contribute to the h-index, its determination is a simpler process. Hirsch has demonstrated that h has high predictive value for whether a scientist has won honors like National Academy membership or the Nobel Prize. The h-index grows as citations accumulate and thus it depends on the "academic age" of a researcher.

The h-index can be manually determined by using citation databases or using automatic tools. Subscription-based databases such as Scopus and the Web of Science provide automated calculators. From July 2011 Google have provided an automatically calculated h-index and i10-index within their own Google Scholar profile.[https://scholar.google.com/intl/en/scholar/citations.html Google Scholar Citations Help], retrieved 2012-09-18. In addition, specific databases, such as the INSPIRE-HEP database can automatically calculate the h-index for researchers working in high energy physics.

Each database is likely to produce a different h for the same scholar, because of different coverage.{{Cite journal |last=Bar-Ilan |first=J. |author-link=Judit Bar-Ilan |year=2007 |title=Which h-index?: A comparison of WoS, Scopus and Google Scholar |journal=Scientometrics |volume=74 |issue=2 |pages=257–271 |doi=10.1007/s11192-008-0216-y |s2cid=29641074}} A detailed study showed that the Web of Science has strong coverage of journal publications, but poor coverage of high impact conferences. Scopus has better coverage of conferences, but poor coverage of publications prior to 1996; Google Scholar has the best coverage of conferences and most journals (though not all), but like Scopus has limited coverage of pre-1990 publications.{{multiref | {{cite journal |last1=Meho |first1=L. I. |last2=Yang |first2=K. |year=2007 |title=Impact of Data Sources on Citation Counts and Rankings of LIS Faculty: Web of Science vs. Scopus and Google Scholar |journal=Journal of the American Society for Information Science and Technology |volume=58 |issue=13 |pages=2105–2125 |doi=10.1002/asi.20677}} | {{Cite arXiv |eprint=cs/0612132 |first=K. |last=Yang |title=A New Era in Citation and Bibliometric Analyses: Web of Science, Scopus, and Google Scholar |date=23 December 2006}} (preprint of paper published as 'Impact of data sources on citation counts and rankings of LIS faculty: Web of Science versus Scopus and Google Scholar', in Journal of the American Society for Information Science and Technology, Vol. 58, No. 13, 2007, 2105–2125)}} The exclusion of conference proceedings papers is a particular problem for scholars in computer science, where conference proceedings are considered an important part of the literature.{{Cite journal |last1=Meyer |first1=Bertrand |author-link1=Bertrand Meyer |last2=Choppy |first2=Christine |last3=Staunstrup |first3=Jørgen |last4=Van Leeuwen |first4=Jan |author-link4=Jan van Leeuwen |year=2009 |title=Research Evaluation for Computer Science |url=http://www.informatics-europe.org/docs/research-eval.php |journal=Communications of the ACM |volume=52 |issue=4 |pages=31–34 |doi=10.1145/1498765.1498780 |s2cid=8625066}}. Google Scholar has been criticized for producing "phantom citations", including gray literature in its citation counts, and failing to follow the rules of Boolean logic when combining search terms.{{Cite journal |last=Jacsó |first=Péter |year=2006 |title=Dubious hit counts and cuckoo's eggs |journal=Online Information Review |volume=30 |issue=2 |pages=188–193 |doi=10.1108/14684520610659201}} For example, the Meho and Yang study found that Google Scholar identified 53% more citations than Web of Science and Scopus combined, but noted that because most of the additional citations reported by Google Scholar were from low-impact journals or conference proceedings, they did not significantly alter the relative ranking of the individuals. It has been suggested that in order to deal with the sometimes wide variation in h for a single academic measured across the possible citation databases, one should assume false negatives in the databases are more problematic than false positives and take the maximum h measured for an academic.{{Cite journal |last=Sanderson |first=Mark |year=2008 |title=Revisiting h measured on UK LIS and IR academics |journal=Journal of the American Society for Information Science and Technology |volume=59 |issue=7 |pages=1184–1190 |citeseerx=10.1.1.474.1990 |doi=10.1002/asi.20771}}

Little systematic investigation has been done on how the h-index behaves over different institutions, nations, times and academic fields.{{Cite journal |last1=Turaga |first1=Kiran K. |last2=Gamblin |first2=T. Clark |date=July 2012 |title=Measuring the Surgical Academic Output of an Institution: The "Institutional" H-Index |journal=Journal of Surgical Education |volume=69 |issue=4 |pages=499–503 |doi=10.1016/j.jsurg.2012.02.004 |pmid=22677589}} Hirsch suggested that, for physicists, a value for h of about 12 might be typical for advancement to tenure (associate professor) at major [US] research universities. A value of about 18 could mean a full professorship, 15–20 could mean a fellowship in the American Physical Society, and 45 or higher could mean membership in the United States National Academy of Sciences.{{Cite news |last=Peterson |first=Ivars |date=December 2, 2005 |title=Rating Researchers |url=http://www.sciencenews.org/view/generic/id/6824/title/Math_Trek__Rating_Researchers |access-date=13 May 2010 |work=Science News}} Hirsch estimated that after 20 years a "successful scientist" would have an h-index of 20, an "outstanding scientist" would have an h-index of 40, and a "truly unique" individual would have an h-index of 60.

For the most highly cited scientists in the period 1983–2002, Hirsch identified the top 10 in the life sciences (in order of decreasing h): Solomon H. Snyder, h = 191; David Baltimore, h = 160; Robert C. Gallo, h = 154; Pierre Chambon, h = 153; Bert Vogelstein, h = 151; Salvador Moncada, h = 143; Charles A. Dinarello, h = 138; Tadamitsu Kishimoto, h = 134; Ronald M. Evans, h = 127; and Ralph L. Brinster, h = 126. Among 36 new inductees in the National Academy of Sciences in biological and biomedical sciences in 2005, the median h-index was 57. However, Hirsch noted that values of h will vary among disparate fields.

Among the 22 scientific disciplines listed in the Essential Science Indicators citation thresholds (thus excluding non-science academics), physics has the second most citations after space science.{{Cite web |date=May 1, 2010 |title=Citation Thresholds (Essential Science Indicators) |url=http://www.sciencewatch.com/about/met/thresholds/ |archive-url=https://web.archive.org/web/20100505011410/http://sciencewatch.com/about/met/thresholds/ |archive-date=5 May 2010 |access-date=13 May 2010 |website=Science Watch |publisher=Thomson Reuters}} During the period between January 1, 2000 and February 28, 2010, a physicist had to receive 2073 citations to be among the most cited 1% of physicists in the world. The threshold for space science is the highest (2236 citations), and physics is followed by clinical medicine (1390) and molecular biology & genetics (1229). Most disciplines, such as environment/ecology (390), have fewer scientists, fewer papers, and fewer citations. Therefore, these disciplines have lower citation thresholds in the Essential Science Indicators, with the lowest citation thresholds observed in social sciences (154), computer science (149), and multidisciplinary sciences (147).

Numbers are very different in social science disciplines: The Impact of the Social Sciences team at London School of Economics found that social scientists in the United Kingdom had lower average h-indices. The h-indices for ("full") professors, based on Google Scholar data ranged from 2.8 (in law), through 3.4 (in political science), 3.7 (in sociology), 6.5 (in geography) and 7.6 (in economics). On average across the disciplines, a professor in the social sciences had an h-index about twice that of a lecturer or a senior lecturer, though the difference was the smallest in geography.{{Cite web |date=19 November 2010 |title=Impact of Social Sciences – 3: Key Measures of Academic Influence |url=https://eprints.lse.ac.uk/35758/1/Handbook_PDF_for_the_LSE_impact_blog_April_2011.pdf |access-date=14 November 2020 |website=Impact of Social Sciences, LSE.ac.uk}}

There are a number of situations in which h may provide misleading information about a scientist's output.{{Cite journal |last=Wendl |first=Michael |author-link=Michael Christopher Wendl |year=2007 |title=H-index: however ranked, citations need context |journal=Nature |volume=449 |issue=7161 |page=403 |bibcode=2007Natur.449..403W |doi=10.1038/449403b |pmid=17898746 |doi-access=free}} The correlation between h-index and scientific awards dropped significantly since 2010 after the widespread usage of h-index, following Goodhart's law. The decrease of correlation is partially attributed to the spread of hyperauthorship with more than 100 coauthors per paper.

Some of the following failures are not exclusive to the h-index but rather shared with other author-level metrics:

• The h-index does not account for the number of authors of a paper. In the original paper, Hirsch suggested partitioning citations among co-authors. One such fractional index is known as fractional h-index, which accounts for multiple authors but is not widely available through the use of automatic tools.
• The h-index does not account for the different typical number of citations in different fields, e.g. experimental over theoretical. Citation behavior in general is affected by field-dependent factors,{{Cite journal |last1=Bornmann |first1=L. |last2=Daniel |first2=H. D. |year=2008 |title=What do citation counts measure? A review of studies on citing behavior |journal=Journal of Documentation |volume=64 |issue=1 |pages=45–80 |doi=10.1108/00220410810844150 |s2cid=17260826 |hdl-access=free |hdl=11858/00-001M-0000-0013-7A94-3}} which may invalidate comparisons not only across disciplines but even within different fields of research of one discipline.{{Cite journal |last1=Anauati |first1=Victoria |last2=Galiani |first2=Sebastian |last3=Gálvez |first3=Ramiro H. |year=2016 |title=Quantifying the Life Cycle of Scholarly Articles Across Fields of Economic Research |journal=Economic Inquiry |volume=54 |issue=2 |pages=1339–1355 |doi=10.1111/ecin.12292 |issn=1465-7295 |s2cid=154806179 |hdl-access=free |hdl=10.1111/ecin.12292}}
• The h-index discards the information contained in author placement in the authors' list, which in some scientific fields is significant though in others it is not.{{Cite journal |last=Sekercioglu |first=Cagan H. |year=2008 |title=Quantifying coauthor contributions |url=http://www.stanford.edu/~cagan/2008%20Sekercioglu%20Science.pdf |journal=Science |volume=322 |issue=5900 |page=371 |doi=10.1126/science.322.5900.371a |pmid=18927373 |s2cid=47571516}}{{Cite journal |last=Zhang |first=Chun-Ting |year=2009 |title=A proposal for calculating weighted citations based on author rank |journal=EMBO Reports |volume=10 |issue=5 |pages=416–417 |doi=10.1038/embor.2009.74 |pmc=2680883 |pmid=19415071}}
• The h-index is an integer, which reduces its discriminatory power. Ruane and Tol therefore propose a rational h-index that interpolates between h and {{nwr|h + 1}}.{{Cite journal |last1=Ruane |first1=F. P. |author-link1=Frances P. Ruane |last2=Tol |first2=R. S. J. |author-link2=Richard Tol |year=2008 |title=Rational (successive) H-indices: An application to economics in the Republic of Ireland |url=https://research.vu.nl/en/publications/7685d226-1cdb-4a7b-832f-e5bcfcb5cf55 |journal=Scientometrics |volume=75 |issue=2 |pages=395–405 |doi=10.1007/s11192-007-1869-7 |s2cid=6541932 |hdl=1871/31768}}

The h-index has been found in one study to have slightly less predictive accuracy and precision than the simpler measure of mean citations per paper.{{Cite journal |last1=Lehmann |first1=Sune |last2=Jackson |first2=Andrew D. |last3=Lautrup |first3=Benny E. |year=2006 |title=Measures for measures |journal=Nature |volume=444 |issue=7122 |pages=1003–1004 |bibcode=2006Natur.444.1003L |doi=10.1038/4441003a |pmid=17183295 |s2cid=3099364}} However, this finding was contradicted by another study by Hirsch.{{Cite journal |last=Hirsch |first=J. E. |year=2007 |title=Does the h-index have predictive power? |journal=PNAS |volume=104 |issue=49 |pages=19193–19198 |arxiv=0708.0646 |bibcode=2007PNAS..10419193H |doi=10.1073/pnas.0707962104 |pmc=2148266 |pmid=18040045 |doi-access=free}} The h-index does not provide a significantly more accurate measure of impact than the total number of citations for a given scholar. In particular, by modeling the distribution of citations among papers as a random integer partition and the h-index as the Durfee square of the partition, Yong{{Cite journal |last=Yong |first=Alexander |year=2014 |title=Critique of Hirsch's Citation Index: A Combinatorial Fermi Problem |url=https://www.ams.org/notices/201409/rnoti-p1040.pdf |journal=Notices of the American Mathematical Society |volume=61 |issue=11 |pages=1040–1050 |arxiv=1402.4357 |doi=10.1090/noti1164 |s2cid=119126314}} arrived at the formula $h\backslash approx\; 0.54\backslash sqrt\; N$, where N is the total number of citations, which, for mathematics members of the National Academy of Sciences, turns out to provide an accurate (with errors typically within 10–20 percent) approximation of h-index in most cases.

Weaknesses apply to the purely quantitative calculation of scientific or academic output. Like other metrics that count citations, the h-index can be manipulated by coercive citation, a practice in which an editor of a journal forces authors to add spurious citations to their own articles before the journal will agree to publish it.{{Cite journal |last1=Wilhite |first1=A. W. |last2=Fong |first2=E. A. |year=2012 |title=Coercive Citation in Academic Publishing |journal=Science |volume=335 |issue=6068 |pages=542–543 |bibcode=2012Sci...335..542W |doi=10.1126/science.1212540 |pmid=22301307 |s2cid=30073305}}{{Cite journal |last=Noorden |first=Richard Van |date=February 6, 2020 |title=Highly cited researcher banned from journal board for citation abuse |journal=Nature |volume=578 |issue=7794 |pages=200–201 |bibcode=2020Natur.578..200V |doi=10.1038/d41586-020-00335-7 |pmid=32047304 |doi-access=free}} The h-index can be manipulated through self-citations,{{Cite journal |last=Gálvez |first=Ramiro H. |date=March 2017 |title=Assessing author self-citation as a mechanism of relevant knowledge diffusion |journal=Scientometrics |volume=111 |issue=3 |pages=1801–1812 |doi=10.1007/s11192-017-2330-1 |s2cid=6863843}}{{Cite journal |last1=Bartneck |first1=Christoph |last2=Kokkelmans |first2=Servaas |year=2011 |title=Detecting h-index manipulation through self-citation analysis |journal=Scientometrics |volume=87 |issue=1 |pages=85–98 |doi=10.1007/s11192-010-0306-5 |pmc=3043246 |pmid=21472020}}{{Cite journal |last1=Ferrara |first1=Emilio |last2=Romero |first2=Alfonso |year=2013 |title=Scientific impact evaluation and the effect of self-citations: Mitigating the bias by discounting the h-index |journal=Journal of the American Society for Information Science and Technology |volume=64 |issue=11 |pages=2332–2339 |arxiv=1202.3119 |doi=10.1002/asi.22976 |s2cid=12693511}}{{multiref | {{Cite journal |last1=Kinouchi |first1=Osame |last2=Cardoso |first2=George C. |year=2018 |title=The K-index and the hubs of science |journal=European Heart Journal |volume=39 |issue=38 |pages=3489–3490 |doi=10.1093/eurheartj/ehy613|pmid=30295763 }} | {{Cite journal |last1=Kinouchi |first1=Osame |last2=Soares |first2=Leonardo D. H. |last3=Cardoso |first3=George Cunha |year=2018 |title=A simple centrality index for scientific social recognition |journal=Physica A: Statistical Mechanics and Its Applications |volume=491 |pages=632–640 |arxiv=1609.05273 |bibcode=2018PhyA..491..632K |doi=10.1016/j.physa.2017.08.072}} }} and if based on Google Scholar output, then even computer-generated documents can be used for that purpose, e.g. using SCIgen.{{Cite report |url=http://rr.liglab.fr/research_report/RR-LIG-008.pdf |title=Ike Antkare one of the great stars in the scientific firmament |last=Labbé |first=Cyril |publisher=Joseph Fourier University |year=2010 |work=Laboratoire d'Informatique de Grenoble RR-LIG-2008 |type=Technical report}} The h-index can be also manipulated by hyperauthorship. Recent research shows clearly that the correlation of the h-index with awards that indicate recognition by the scientific community has substantially declined.{{Cite journal |last1=Koltun |first1=Vladlen |last2=Hafner |first2=David |year=2021 |title=The h-index is no longer an effective correlate of scientific reputation |journal=PLOS ONE |volume=16 |issue=6 |pages=e0253397 |arxiv=2102.03234 |bibcode=2021PLoSO..1653397K |doi=10.1371/journal.pone.0253397 |pmc=8238192 |pmid=34181681 |doi-access=free}}

Various proposals to modify the h-index in order to emphasize different features have been made.{{Cite journal |last1=Batista |first1=P. D. |last2=Campiteli |first2=Mônica G. |last3=Kinouchi |first3=Osame |display-authors=1 |year=2006 |title=Is it possible to compare researchers with different scientific interests? |journal=Scientometrics |volume=68 |issue=1 |pages=179–189 |arxiv=physics/0509048 |doi=10.1007/s11192-006-0090-4 |s2cid=119068816}}{{Cite journal |last1=Dimitrios |first1=Katsaros |last2=Manolopoulos |first2=Yannis |year=2007 |title=Generalized Hirsch h-index for disclosing latent facts in citation networks |journal=Scientometrics |volume=72 |issue=2 |pages=253–280 |citeseerx=10.1.1.76.3617 |doi=10.1007/s11192-007-1722-z |s2cid=14919467}}{{Cite journal |last=Vaidya |first=Jayant S. |date=December 2005 |title=V-index: A fairer index to quantify an individual's research output capacity |journal=BMJ |volume=331 |issue=7528 |pages=1339–1340 |doi=10.1136/bmj.331.7528.1339-c |pmc=1298903 |pmid=16322034}}Katsaros D., Sidiropoulos A., Manolopous Y., (2007), [http://sunsite.informatik.rwth-aachen.de/Publications/CEUR-WS//Vol-245/paper3.pdf Age Decaying H-Index for Social Network of Citations] in Proceedings of [http://ceur-ws.org/Vol-245/ Workshop on Social Aspects of the Web Poznan, Poland, April 27, 2007]{{Cite journal |last1=Anderson |first1=Thomas R. |last2=Hankin |first2=Robin K. S. |last3=Killworth |first3=Peter D. |date=12 July 2008 |title=Beyond the Durfee square: Enhancing the h-index to score total publication output |journal=Scientometrics |publisher=Springer |volume=76 |issue=3 |pages=577–588 |doi=10.1007/s11192-007-2071-2 |issn=0138-9130 |doi-access=free}}{{Cite journal |last1=Baldock |first1=Clive |last2=Ma |first2=Ruimin |last3=Orton |first3=Colin G. |date=5 March 2009 |title=The h index is the best measure of a scientist's research productivity |journal=Medical Physics |publisher=Wiley |volume=36 |issue=4 |pages=1043–1045 |bibcode=2009MedPh..36.1043B |doi=10.1118/1.3089421 |issn=0094-2405 |pmid=19472608}} Many of these variants, such as g-index, are highly correlated with the original h-index, which has led some researchers to consider them redundant.{{Cite journal |last=Bornmann |first=L. |display-authors=etal |year=2011 |title=A multilevel meta-analysis of studies reporting correlations between the h-index and 37 different h-index variants |journal=Journal of Informetrics |volume=5 |issue=3 |pages=346–359 |doi=10.1016/j.joi.2011.01.006}}

One metric which was found not to be highly correlated with h-index and is correlated with scientific awards as of 2019 is the fractional h-index.{{Cite journal |last1=Koltun |first1=V |last2=Hafner |first2=D. |year=2021 |title=The h-index is no longer an effective correlate of scientific reputation |journal=PLOS ONE |volume=16 |issue=6 |pages=e0253397 |arxiv=2102.03234 |bibcode=2021PLoSO..1653397K |doi=10.1371/journal.pone.0253397 |pmc=8238192 |pmid=34181681 |quote=Our results suggest that the use of the h-index in ranking scientists should be reconsidered, and that fractional allocation measures such as h-frac provide more robust alternatives |doi-access=free}} [https://h-frac.org Companion webpage]

A Hirsch-type index for institutions has also been devised.{{Cite journal |last=Kosmulski |first=M. |year=2006 |title=I – a bibliometric index |journal=Forum Akademickie |volume=11 |page=31}}{{Cite journal |last=Prathap |first=G. |year=2006 |title=Hirsch-type indices for ranking institutions' scientific research output |journal=Current Science |volume=91 |issue=11 |page=1439}} A scientific institution has a successive Hirsch-type index of i when at least i researchers from that institution have an h-index of at least i.

The h-index has been applied to internet media, such as YouTube channels. It is defined as the number of videos h a channel has with more than h × 10⁵ views. When compared with a video creator's total view count, the h-index and g-index better capture both productivity and impact in a single metric.{{Cite journal |last=Hovden |first=R. |year=2013 |title=Bibliometrics for Internet media: Applying the h-index to YouTube |journal=Journal of the American Society for Information Science and Technology |volume=64 |issue=11 |pages=2326–2331 |arxiv=1303.0766 |doi=10.1002/asi.22936 |s2cid=38708903}}

More recently, a dual framework distinguishing between *disruptive* and *consolidating* scientific impact has led to the development of new h-index variants.{{Cite journal |last1=Yang |first1=Alex J. |last2=Hu |first2=Haojia |last3=Zhao |first3=Yifei |display-authors=1 |year=2023 |title=From consolidation to disruption: A novel way to measure the impact of scientists and identify laureates |journal=Information Processing & Management |volume=60 |issue= |pages=103420 |doi=10.1016/j.ipm.2023.103420}} Introduced in 2023, this approach uses citation network analysis to define:

• Scientists' Disruptive Citation (SDC) and Scientists' Consolidating Citation (SCC): These metrics sum the disruptive citations (DC, reflecting divergence from prior work) and consolidating citations (CC, indicating incremental contributions) across a scientist’s publications, respectively.
• Disruptive h-index (D h-index): The maximum number of papers by a scientist with at least that number of disruptive citations, emphasizing innovative influence.
• Consolidating h-index (C h-index): The maximum number of papers with at least that number of consolidating citations, highlighting reinforcement of existing research.

Studies have shown that SDC and D h-index outperform traditional metrics (e.g., h-index, total citations) in identifying award-winning scientists, such as Nobel laureates, and are less susceptible to manipulation than earlier disruption-based measures.{{Cite journal |last1=Yang |first1=Alex J. |last2=Deng |first2=Siyu |year=2024 |title=Dynamic patterns of the disruptive and consolidating knowledge flows in Nobel-winning scientific breakthroughs |journal=Quantitative Science Studies |volume= |issue= |pages=1–17 |doi=10.1162/qss_a_00323|doi-access=free }} Further research suggests that disruptive papers, as measured by these metrics, may also predict broader technological and societal impact.{{Cite journal |last1=Yang |first1=Alex J. |last2=Yan |first2=Xiao |last3=Hu |first3=Haojia |display-authors=1 |year=2025 |title=Are disruptive papers more likely to impact technology and society? |journal=Journal of the Association for Information Science and Technology |volume=76 |issue= |pages=563–579 |doi=10.1002/asi.24947}}

• Bibliometrics
• Comparison of research networking tools and research profiling systems
• Science-wide author databases of standardized citation indicators

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{{Refend}}

• [https://scholar.google.com/intl/en/scholar/metrics.html Google Scholar Metrics]
• [http://www.guide2research.com H-index for computer science and electronics]
• [http://ideas.repec.org/top/top.person.hindex.html H-index for economists]
• [http://www.cs.ucla.edu/~palsberg/h-number.html H-index for computer science researchers]
• [http://www.guide2research.com/scientists/ H - index for computer scientists from Google Scholar]
• [https://ui.adsabs.harvard.edu H-index for astronomers]
• [https://www.rosenberglab.net/impact.html Publication and Citation-based Impact], listing 252 impact measures for one researcher with link to source code

{{Academic publishing}}

{{Authority control}}

{{DEFAULTSORT:H-Index}}

Category:Citation metrics

Category:University and college rankings