LibGuides: Faculty Publishing: Measuring Impact

Citation Counts

One measure of the impact of an individual article is counting the number of times it has been cited. This can be done through a number of databases and software applications. Please note that some disciplines are more heavily cited than others, and also that citation counts will vary from one source to another, depending on the number of and type of sources indexed per database.

There are also a number of alternative metrics, called altmetrics, that can be used to measure an article's impact. The altmetrics section has more information.

Journal Citation Reports (ISI Web of Science)
Compare selected journals, look up Eigenfactor, journal impact factor, top papers by research field and data visualizations.
Scopus - CiteScore metrics
Calculated using data from Scopus, CiteScore metrics help you evaluate journals, book series, conference proceedings and trade journals to empower well-informed decisions.
PLOS One
In addition to providing citation counts, each source listed in the search results has number of views, number of bookmarks, and number of shares in social media.
Google Scholar Top Publications

h-Index (Hirsch Index)

The Hirsch index, more widely known as the h-index, is a measure of an author's (or group of authors' or journal's) scholarly impact. The h-index reflects both the number of publications and the number of citations per publication. An author with an h-index=12 has at least 12 papers that have each been cited 12 times. Where to find an author's h-index?:

Publish or Perish (Harzing)
A software program that reports h-index based on citation counts from Google Scholar and from Microsoft Academic Search.

Web of Science
A database of all of the Web of Science Citation indexes, including 8500 international journals in the sciences, social sciences, and arts and humanities. Perform an Author Search; on the search results page, click on "Create Citation Report" to view the h-index.

What are some limitations to the h-index?

As with JCR, the h-index is not a fair means of comparing authors across subject areas, as some disciplines naturally publish and cite more than others.
Because the h-index is calculated using the number of a researcher's publications, and therefore reflects an author's "scholarly age," persons with shorter career spans are at a disadvantage, regardless of the importance of their discoveries.
An author's h-index will be invalid if another researcher has the same name; for this reason, the only truly reliable means of deriving an author's h-index is to use a list of publications provided by the author him/herself.
The h-index does not account for self-citations or negative citations, and may, therefore, misrepresent an author's importance .
When calculating an author's h-index using Web of Science, bear in mind that the author's books, book chapters, etc., will not be included; furthermore, the social sciences and humanities are not well represented within Web of Science.

Other Journal Metrics

American Psychological Association (APA) Journal Statistics
Statistics about manuscript rejection rates, circulation data, publication lag time, and more, from the APA.
Excellence in Research for Australia (ERA)
ERA identifies and promotes excellence across the full spectrum of research activity in Australia’s higher education institutions.

Through ERA the ARC is tasked with identifying excellence in research, by comparing Australia's university research effort against international benchmarks, creating incentives to improve the quality of research and identifying emerging research areas and opportunities for further development.
The next round of ERA is underway for 2018.
Eigenfactor
The Eigenfactor ranks journals based on the number of citations its articles receive, weighting citations that come from other influential journals more heavily. A benefit of the Eigenfactor over the JIF is that it excludes self-citations.

The Article Influence score is the Eigenfactor divided by the number of articles in the journal. This metric is most directly comparable to the JIF.
Google Scholar Metrics
In addition to measuring an author's impact, h-index can also measure the impact of journals. To get started, browse the top 100 publications (available in several languages), ordered by their five-year h-index and h-median metrics. To see which articles in a publication were cited the most and who cited them, click on its h-index number to view the articles as well as the citations underlying the metrics.
Harzing Journal Quality List
The most comprehensive directory of periodicals or serials available worldwide. Provides bibliographic information on 240,000+ journals, magazines, and newspapers.
CiteScore; SNIP; JCR; SJR
The IPP measures the ratio of citations in a year (Y) to scholarly papers published in the three previous years (Y-1, Y-2, Y-3) divided by the number of scholarly papers published in those same years (Y-1, Y-2, Y-3).
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CiteScore: Ratio: the number of citations a journal receives in one year to documents published in the previous three years, divided by the number of documents indexed in Scopus published in the same three years. Think of it as a competitor to Impact Factor, in that it uses a similar citation-based formula, but CiteScore: covers more journals (provider Elsevier claims it covers "twice as many journals than have an Impact Factor"; considers "documents" beyond just journal articles, such as editorials, books, conference proceedings, etc; and seeks to be a more transparent and reproducible metric.

SNIP: Source Normalized Impact per Paper measures contextual citation impact by weighting citations based on the total number of citations in a subject field.

Journal Citation Reports (JCR) provides an analytical method for determining the quality of a particular scholarly journal compared to other journals in its field. JCR uses a ratio known as the impact factor to identify a journal's standing. JCR allows you to evaluate and compare journals using citation bibliometrics data drawn from over 11,000 scholarly and technical journals from more than 3,300 publishers in over 80 countries. JCR provides information on the most frequently cited journals in a field, the highest impact journals in a field, and the largest journals in a field. Updated to new InCites interface. Also provides access to Endnote Basic, a free citation management program.

SJR: SCImago Journal Rank is a prestige metric based on the idea that 'all citations are not created equal'. With SJR, the subject field, quality and reputation of the journal have a direct effect on the value of a citation.
SJR - SCImago Journal Rank
SJR is a measure of scientific influence of scholarly journals that accounts for both the number of citations received by a journal and the importance or prestige of the journals where such citations come from.

The Shape of Science is an information visualization project whose aim is to reveal the structure of science. Its interface has been designed to access the bibliometric indicators database of the SCImago Journal & Country Rank portal.
CWTS Journal Indicators, including SNIP
Created by Professor Henk Moed at CTWS, University of Leiden, Source Normalized Impact per Paper (SNIP) measures contextual citation impact by weighting citations based on the total number of citations in a subject field. The impact of a single citation is given higher value in subject areas where citations are less likely, and vice versa.
Transparency Index
An article in The Scientist examines the concept of a Transparency Index.

Journal Impact Factor

The journal impact factor (JIF) measures the frequency with which the 'average article' published in a journal has been cited in a particular year. It measures a journal's relative importance as it compares to other journals in the same field. The JIF is a well-known and well-established metric.

What are some limitations to the journal impact factor?

Journal Citation Reports (Web of Science) has very few open access journals, books and conference proceedings, and a finite number of journals. Most of these are English-language only.
Because the JIF is calculated using data from a two or five year period, new journals are excluded. As well, many small journals are not represented.
Journal titles are assigned to one or more subject categories in JCR; therefore, the same journal may be ranked differently depending on the category being reviewed.
Citation practices vary from one field to another, precluding comparisons across different subject areas.
Having a large number of citations is not necessarily a marker of merit, as articles can sometimes be cited for negative reasons.
Large and multidisciplinary journals will have higher Journal Impact Factors than those that are more focused.
Journal impact factors can be manipulated by authors self-citing, by groups of authors citing each other's work, by an increase in multiple authorship of papers, and by certain editorial practices, such as publishing numerous review articles.

Where can I find a journal's impact factor?

Web of Science ISI - Journal Citation Reports

Attribution

This page is modeled after and adapted from: "Scholarly Metrics" Library. Simon Fraser University. n.d. Web. 27 Oct. 2015.