Types of metrics and where to find them
In simple terms, scholarly metrics are quantitative and qualitative measures of the impact of academic works. They can be used at the artifact (e.g., book, article), journal, author, or institutional level. Scholarly metrics can range from tracking citations to measuring downloads or mentions on social media. While there are specific tools dedicated to scholarly metrics such as Scopus and Web of Science, less obvious sources for scholarly metrics could be article databases, Google Scholar, library catalogs, publisher websites, and social media platforms. Although journals come to mind most often when thinking about scholarly metrics, impact can be tracked with metrics for other scholarly outputs such as books and creative works (performances, paintings).
This guide covers some of the more popular measures of journal, author, and article impact. Many of these metrics are proprietary to specific companies. When using research metrics, keep in mind:
* Metrics are not a substitute for informed, qualitative assessment.
* Metrics should be easy to understand, transparent, and open.
* Different contexts and disciplines may require different sets of metrics.
Meaningful Metrics by Call Number: eBookISBN: 9780838987551Publication Date: 2015All in one resource starting with the essential histories of bibliometrics and altmetrics, and continuing with in-depth descriptions of the core tools and emerging issues at stake in the future of both fields.
Demystifying Scholarly Metrics: A Practical Guide by Call Number: Request via ILLISBN: 1440875936Publication Date: 2022Demystifying Scholarly Metrics gives librarians and faculty the confidence to navigate the maze of scholarly metrics, identify quality journals in which to publish, and measure the impact of scholarly works.
Looking at journal rankings can help to identify top journals in a field or when comparing a few journals. Rankings are based on the measure of how often a journal's articles are cited by other publications. Selection can then be informed by understanding the citation rate and number of article downloads for a given journal.
Be aware that competing journal evaluation resources use a variety of calculations based on the citing publications included in their databases. Some databases, such as JCR, use a selective list of prestigious journals as well as a handful of books and conference proceedings. Other databases, such as Google Scholar, cover a wider variety of publications that includes low-quality journals, unpublished documents, and a significant number of books.
Journal Citation Report (JCR): The Impact Factor (JIF)
A subscription service from Clarivate. Note that the JCR covers far fewer journals than the Web of Science database (also part of Clarivate).
The JIF refers to the average number of articles in a journal that were cited 1 to 2 years ago, If a journal has a JIF of three in 2021, it means that articles published in 2020 and 2019 were cited an average of three times.
- Journal Citation Reports This link opens in a new window
An annual publication by Clarivate Analytics that analyzes, compares, and ranks scholarly and technical journals tracked in the Web of Science. Coverage includes virtually all disciplines in the areas of science, social sciences, and humanities. The report contains data on the citation performance of academic journals indexed in Web of Science, including information on the number of articles published, the number of times articles have been cited, the journal impact factor, and other citation metrics. JCR is a trusted source for finding journal ranking but it does not cover all journals. (Coverage: 1997 --)
SCImago: SCImago Journal Rank (SJR)
An open source portal that uses citation calculations to rank both journals and the overall research productivity of countries. The journals included in SCImago are drawn from the Scopus database. Citing documents are primarily journals, but some conference proceedings and books are included as well.
The quartile feature divides the journal ranking into four equal groups which is useful for seeing the relative prestige of journals in a category. Thus, a journal in the first quartile is in the top 25% for that category, second quartile journals are in the top 50%, and so forth.
The SJR refers to the average number of articles in a journal that were cited 1 to 3 years ago. If a journal has a JIF of four in 2021, it means that articles published in 2020, 2019, and 2018 were cited an average of four times.
- SCImago Journal & Country RankA publicly available portal that includes the journals and country scientific indicators developed from the information contained in the Scopus® database (Elsevier B.V.).
Scopus Journal Metrics
The Scopus website has a number of journal metrics which can be freely accessed. The library's subscription to Scopus database offers more features for working with search results.
CiteScore - Similar to Journal Impact Factor, CiteScore measures the citation impact of a journal using a 4-year window for citation analysis of the documents in its database.
Calculated annually: CiteScore 2023 counts the citations received in 2020-2023 to articles, reviews, conference papers, book chapters and data papers published in 2020-2023, and divides this by the number of publications published in 2020-2023.
% Cited - measures the percentage of articles in a journal that were cited. A helpful metric to determine if a handful of articles is driving a journal's prestige.
Source-normalized Impact per Paper (SNIP) - a journal impact metric that accounts for disciplinary differences in order to make comparisons between fields. It compares a journal’s citations per publication with the citation potential of its field. A field is defined as the set of publications citing that journal.
SJR (SCImago Journal Rank): A prestige metric for journals, book series and conference proceedings that weights the value of a citation based on the subject field, quality and reputation of the source.
- Scopus metrics for journalsJournal metrics freely available the Sources page of the Scopus website include CiteScore, % Cited, SNIP and SJR. Source details page lists basic source information and journal metric scores for Scopus journals, book series, conference proceedings, and trade publications.
- Scopus This link opens in a new window
A citation and abstracting database covering thousands of active titles, primarily peer-reviewed journals. Also includes eBooks, major reference works and graduate level textbooks. Emphasis on social sciences, arts and humanities, but also includes science, technology and medicine. Includes thousands of Open Access journals, conference proceedings, trade publications, book series, and patents. (Coverage: Primarily 1970-present. Some pre-1970 records going back to 1788)
Google Scholar Metrics (GSM)
An open-source journal-ranking tool that ranks the top 100 journals and provides ranking for specific disciplines. Journals are evaluated using the h-index (a metric more commonly used to evaluate authors).
A journal with an h-index of 15 means that it has published at least 15 articles that received at least 15 citations. The GSM collects citations over the last 5 full years to further refine this metric.
Most author level metrics incorporate citation counts of articles written. The best sources of traditional author level metrics are databases such as Web of Science, Scopus and Google Scholar. Be aware that there will be differences in citation counts between databases depending on their coverage of the literature and publication periods. The h-index metric can be calculated for many entities - authors, journals, departments. It only requires a collection of cited articles over time.
h-index
For an author, the h-index means that the author has published X number of article which have each been cited at least X number of times. So an h index of 15 means that the author has published at least 15 articles which have each been cited at least 15 times. It is designed to look at overall productivity rather than just a raw citation count, which can be influenced by 1 or 2 highly cited articles.
Google Scholar is an open resource to find h-indices of authors who have a public Google Scholar profile.
- Google Scholar ProfileEnter name of author. Try the full name or the first initial and last name.
Scopus and Web of Science provide convenient search features for locating authors' h-indices. Make use of options to search with authors' affiliations or ORCID iDs to disambiguate between common or similar author names.
- Scopus This link opens in a new window
A citation and abstracting database covering thousands of active titles, primarily peer-reviewed journals. Also includes eBooks, major reference works and graduate level textbooks. Emphasis on social sciences, arts and humanities, but also includes science, technology and medicine. Includes thousands of Open Access journals, conference proceedings, trade publications, book series, and patents. (Coverage: Primarily 1970-present. Some pre-1970 records going back to 1788)
- Web of Science This link opens in a new window
A reference and citation index comprised of several databases that can be searched as a whole or individually. Provides access to data from scholarly literature in the sciences, social sciences, arts, and humanities as published in journals, conference proceedings, symposia, seminars, colloquia. workshops, and conventions across the world. To search in a subset rather than all components at once, select a database and then select the desired index or indices in the “Editions” dropdown menu.
Limitations of h-indices
Not appropriate for field comparisons
Because of disciplinary differences in publication frequency and citation habits, h-indices should not be compared for researchers from different fields. In general, researchers in the sciences have higher citation counts than those in the humanities, but there are differences even between science fields: chemists have higher h-indices than physicist, who in turn have higher h-indices than computer scientists.
Doesn't reflect high impact research
The h-index is insensitive to high "outliers" -- a few papers that have very high citation counts will not sway the h-index score (much). Multiauthorships is another issue that the h-index does not take into account. Not all co-authors necessarily contribute equally to a paper, but all will benefit equally from the citation count.
Disadvantages early career researchers
Early career researchers need several years to publish papers and accumulate citations in order to achieve high h-indices, and therefore, should not be compared to more established researchers
The category of publication-level metrics refers to citations to books, articles, data sets, and conference proceedings. Researchers have several options for locating citations to their scholarly works. Citation databases, such as Web of Science, Scopus, or Google Scholar, are the most efficient being designed for locating citations.
Web of Science
The oldest citation index with the best name recognition, Web of Science (from Clarivate) indexes a highly selective list of publications (journals, conference proceedings and books). Use the "Cited References" search feature to find the citation count for a given publication. Access an author's profile to find a list of the researcher's works and their citations. You can also sort search results by how often documents were cited.
Please note: The citation count will only include the number of times the publication was cited by specific articles from the journals that Web of Science covers. Web of Science does not count citations from every journal published around the world, nor does it count citations from books, conference proceedings, dissertations/theses, patents, technical reports or other types of publications.
- Web of Science This link opens in a new window
A reference and citation index comprised of several databases that can be searched as a whole or individually. Provides access to data from scholarly literature in the sciences, social sciences, arts, and humanities as published in journals, conference proceedings, symposia, seminars, colloquia. workshops, and conventions across the world. To search in a subset rather than all components at once, select a database and then select the desired index or indices in the “Editions” dropdown menu.
Scopus
Scopus is a citation index from Elsevier which covers a broader range of journals and books than Web of Science. You can access your author's profile to view all of the citations to your work. You can also sort search results by how often documents were cited.
Beyond simple citation counts, Scopus includes some benchmarks to place authors' citations in context. Percentile benchmarking shows how one's citations compare to other works in the same discipline. The Field-Weighted Citation Impact (FWCI) metric demonstrates how often a scholarly work is cited compared to similar works. The FWCI also takes into account the type of work (article, conference proceeding, book), year of publication, and academic discipline, as well as disciplinary differences.
- Scopus This link opens in a new window
A citation and abstracting database covering thousands of active titles, primarily peer-reviewed journals. Also includes eBooks, major reference works and graduate level textbooks. Emphasis on social sciences, arts and humanities, but also includes science, technology and medicine. Includes thousands of Open Access journals, conference proceedings, trade publications, book series, and patents. (Coverage: Primarily 1970-present. Some pre-1970 records going back to 1788)
Google Scholar
Google Scholar crawls the web for publications to index resulting in an open source, comprehensive citation index. More extensive in coverage than Web of Science and Scopus, the number of journals and books indexed is unknown due to a lack of transparency, and there is no editorial control of the quality of sources. However, Google Scholar appears to provide the most comprehensive coverage for citations to books.
- Google Scholar This link opens in a new window
Partial Open Access. Search engine specifically for scholarly publications. You can access the full-text of articles from open access and preprint publications, but you must be logged in to your UDel email account in order to access subscriptions provided by the UD Library.
A note about Google Scholar
Google Scholar is the best known open resource that is the most comprehensive citation index. This resource trawls the web for publications to include although there is a lack of transparency in the coverage. Many kinds of scholarly information are indexed including journal articles, books and book chapters, conference proceedings, dissertations, teaching materials, etc. With no editorial control of the quality of the sources or deduplication efforts, low quality materials, inflated citation counts, and incorrect attributions can occur. However, Google Scholar appears to provide the most comprehensive coverage of citations to books.
Google Scholar Metrics: Journals
Google Scholar Metrics provides information about journal rankings and ratings by various metrics. Browse the top 100 publication titles in 9 different languages, or search by broad subject research areas and numerous subcategories. Scholar Metrics uses those articles published over a 5-year period and citations from all articles indexed in Google Scholar as it was in July 2024 (consult site for latest date information). Overall, Scholar Metrics covers a substantial fraction of scholarly articles but doesn't currently cover a large number of articles from smaller publications.
Journal h-index in Google Scholar
Google Scholar indexes many kinds of scholarly information including journal articles, books and book chapters, conference proceedings, dissertations, teaching materials, etc. Google Scholar provides an h5 Index for most journals (h index for the most recent 5 full years) and also offers subject categories, ranking journals listed within each category.
To check a journal's h5 Index follow these steps:
* open the Menu and select Metrics
* click on the "search" icon
* type in the title of the journal - you may need to try more than one spelling (e.g. with or without ampersand, alternate title, abbreviated title)
* the h5-index and h5-median will appear if available
* select the hyperlinked h5-index number to view the h5-core (articles cited at least h times) and to see if the journal is in the top 20 of a subject category
h5-index is the h-index for articles published in the last 5 complete years. It is the largest number h such that h articles published in 2019-2023 have at least h citations each.
h5-median for a publication is the median number of citations for the articles that make up its h5-index.
Google Scholar: Books
In addition to journal articles, Google Scholar also indexes books, book chapters and other non-traditional sources such as promotional pages, table of contents pages, course reading lists etc. Caveats: Google Scholar is not as accurate as Scopus since it cannot remove self-citations and may include multiple entries for one work which can inflate results.
Google Scholar: Profile
Google Scholar Profiles provide a simple way for authors to showcase their academic publications. You can check who is citing your articles, graph citations over time, and compute several citation metrics. You can also make your profile public, so that it may appear in Google Scholar results when people search for your name
- Google Scholar ProfileEnter name of author. Try the full name or the first initial and last name.
Establish a Researcher ID
A Research Identifier is a persistent digital identifier or unique identifier assigned to a researcher. Advantages of having an identifier:
* Allows a researcher to connect all research outputs together
* For researchers with common names, ID's provide a way to identify and claim only their scholarship
* Collects all versions of a researcher's name
* Collects output researcher many have published under a previous name
* Saves data entry time, different systems linked to ID will store the needed information
Common ID's
ORCiD – is an effort to connect all researcher ID systems together. You can create a profile, and link it to your Scopus ID, ResearchID, and other systems. Many publishers now request or even require ORCiD ID's at submission.
Web of Science ResearcherID – Users who do not have a Web of Science subscription can register and sign in to create and manage their free Web of Science Researcher Profile. Researcher ID is also important as a basis to provide feedback to Web of Science for grouping author name variants or corrections to affiliations.
Scopus Author Profile – helps author recognition and disambiguation when searching publications. Many researchers already have a Scopus ID without realizing it. You can still claim and manage your Scopus Author ID by establishing an account in Scopus.
Each Scopus Author Profile is a unique record of that researcher’s publication activity. The details come from peer-reviewed articles and other publications that are indexed in Scopus (published in journals, books and other sources, that the Scopus Content Selection and Advisory Board has selected for inclusion and indexing) where the researcher is specified as an author. The information in a profile includes the author name, affiliation(s), subject area(s), publications, citations, and co-authors. The profiles do not cover editorship, managerial or executive roles, or teaching positions.
Google Scholar – Create an identity by clicking "My Profile." This creates a link for your name in Google Scholar and brings together all your research on one page
- Scopus Author ProfileYou can use this free author lookup to search for any author
- Google Scholar ProfileEnter name of author. Try the full name or the first initial and last name.