Guide to Journal Metrics and How to Measure Your Impact Factor

Journal metrics are a type of quantative, bibliometric data that is used to measure the quality and impact of any given scholarly journal. There are different types of journal metrics offered and each is calculated slightly differently. You can discover the most important journal metrics below.

Journal metrics matter because they help scholars to choose which journal to publish in by letting them compare and evaluate if the journal is a good fit for their research.

Journal metrics are also relevant for journal editors to help them put the quality of the work they are publishing into a wider context and benchmark their output with other journals.

The Journal Impact Factor (JIF), or simply Impact Factor (IF), is probably the most well-known journal metric. The term was first coined in the 1960s by Eugene Garfield, the founder of the Institute for Scientific Information. Today, the company Clarivate calculates and provides the Journal Impact Factor based on citation data from their own, paid-access database Web of Science.

The Journal Impact Factor (JIF) assesses how frequently a journal article has been cited each year. New JIFs are released every year and calculated by the number of times articles published in the previous two years have been cited.

How to Find the Impact Factor for a Journal

The Journal Impact Factor is updated once a year and can usually be found on a journal’s website.

Generally said, the Journal Impact Factor measures the average number of times an article in a particular journal is cited in a particular year. It is the ratio between citations and citable items published in the preceding two or five years. When talking about the Journal Impact Factor, it is usually the two-year Journal Impact Factor that is meant.

An example: If a journal received a two-year Journal Impact Factor of 3 in the year 2021, it means that articles published in the years 2019 and 2020 have been cited on average three times in 2021. However, it’s important to keep in mind that this is only an average value. Some highly influential articles will be cited much more often, while others will receive less or even no citations. This is one reason to look beyond the Journal Impact Factor when trying to find the right journal.

What is a Good Impact Factor? Interpreting JIFs

What is considered a “good” impact factor varies from field to field. Generally, speaking, a Journal Impact Factor of 3 or higher is considered good. JIFs of 10 or higher are considered excellent.

There are many journals that have journal impact factors below or between 1 and 3, which is considered average. Again, it is important to know that you should consider more than one metric when evaluating journals, as a journal’s quality and impact rests on multiple factors and not just one single number.

CiteScore: A Key Alternative from Scopus

The CiteScore (CS) of a journal is based on citations in the SCOPUS database, which was launched in 2004 and is owned by the academic publishing company Elsevier. The metric itself has been around since 2017 and has become a serious competitor to the Journal Impact Factor.

Similar to the Web of Science database, a journal must comply with a number of criteria to be included in SCOPUS.

Like the Journal Impact Factor, the CiteScore measures how often an article in a particular journal is cited in a specific year on average. However, the CiteScore looks at a four-year citation window, claiming it to be a good compromise for fast- and slow-moving fields. It is calculated by forming the ratio between citations to articles published in the last four years (including the CiteScore year) and the number of articles published in those same four years.

SCImago Journal Rank (SJR) and Source Normalized Impact per Paper (SNIP)

The SCImago Journal Rank, based on the SCOPUS database, measures the scientific influence of a scholarly journal by taking into account the number of citations received by a journal as well as the prestige of the journals from which the citations originate.

The SJR does not eliminate self-citations and looks at a three-year citation window instead of five.

The Source Normalized Impact per Paper (SNIP) weighs citations differently based on the total number of citations in a subject field. That means it contextualizes, or “balances”, citation impact. In subject areas with low citation frequencies, the impact of a single citation is rated higher than in subject areas where citations are more likely – and vice versa.

Subject fields with typically lower citation frequencies are, for example, mathematics, social sciences and the humanities. Subject fields with higher citation frequencies are usually among the STM disciplines (science, technology and medicine).

Journal Citation Indicator (JCI) and Eigenfactor

The Journal Citation Indicator (JCI) was developed to complement the JIF by taking different variables into account, like a journal’s subject area, document types and years of publication.

The JCI uses the Category Normalized Citation Impact (CNCI) tool which calculates the figure by dividing the actual count of citable items by the expected citation rate for documents with the same document type, year of publication and subject area.

The Eigenfactor was first presented by Clarivate in 2006 as an alternative to the Journal Impact Factor. The creators’ idea was to create a different way of looking at citation data by weighing citations differently, depending on the prestige of the contributing journal.

Eigenfactor concerns only journals that are part of the Journal Citation Reports. It measures how often a journal has been cited in the past five years, while eliminating journal self-citations. Citations by highly cited journals influence the score more than those by lower-tier journals.

Eigenfactor scores are scaled so that the sum of the Eigenfactor scores of all journals listed in the Journal Citation Reports is 100.

Journal Quartiles (Q1-Q4): What They Mean for Rankings

Journal Quartiles are a kind of tier system to rank journals by their impact and influence in a certain field. Using common journal metrics like the Journal Impact Factor (JIF) or the Scimago Journal Rank (SJR), journals are divided into four quartiles – Q1, Q2, Q3, and Q4 – within their subject category and based on their ranking compared to other journals in the same subject category.

For example: If you are looking at 100 journals in a subject category, then the journals would be placed into the following quartiles dependent on their rank:

• Q1 (Top 25%): Ranks 1–25
• Q2 (25–50%): Ranks 26–50
• Q3 (50–75%): Ranks 51–75
• Q4 (Bottom 25%): Ranks 76–100

Q1 is the highest tier and includes the most prestigious journals. These journals are more difficult to publish in. In that same vein, Q4 is the lowest tier and includes journals that are not cited as often and have the least amount of influence.

Article-Level Metrics: Citations, Usage, and Altmetrics

Next to looking at journal metrics, you can also assess the impact of your work by looking at other quantitative measures on the article-level. For a comprehensive assessment, make sure to look at several if not all of these metrics and to also ask for some of that qualitative feedback as well.

1. Citations have long been considered the primary metric to be used to assess the quality of an article. Citations track when and where your peers credit and reference your research in their own work and are an important way of validating your research.
   
   However, there are limitations to relying on citation data alone. Since the formation of DORA, the San Francisco Declaration on Research Assessment, there has been a call for the research community to explore other metrics that can be used alongside citation data, giving a broad range of impact measures that include influence on policy and practice.
   
2. Usage refers to the number of times your article has been read online. This can be reported as the number of times the PDF version of your article has been downloaded or the number of times the version on the journal webpage has been viewed. These figures can also be combined.
   
   The usage figure of your article is a good way to gauge the reach of your article. More people reading your work could possibly result in more citations. You can increase the reach and readership of your article by sharing and promoting it after it’s published.
3. Altmetric uses a range of data sources to provide a comprehensive report on the attention your work is receiving. Going beyond just citations and usage, the Almetric Attention Score tracks multiple online sources and gives you a visual representation of the ‘influence’ of your research, also known as the "Altmetric donut."
   
   In addition to the different sources of attention, Altmetric also tracks citations from Dimensions and readers on Mendeley.

The benefit of using the Altmetric Attention Score is that you gain insight into who is talking about your research and what they are saying in addition to traditional metrics. Your article’s Altmetric Attention Score can also be valuable for identifying people within your subject field to collaborate with.

You can find the Altmetric Attention Score for your work on the article page or through the Altmetric Bookmarklet.

The h-index, named after its inventor Jorge E. Hirsch, is an author-level metric, which indicates the academic impact of a researcher based on quantity and quality of their output. It is calculated by counting the number of publications by an author that have been cited by others at least as often. For example, a scholar with an h-index of 5 has published 5 papers, each of which has been cited at least 5 times.

SCOPUS, Web of Science as well as Google Scholar and other citation databases provide calculations of the h-index. It is frequently used in the assessment of job candidates for academic positions as well as the allocation of research grants.

Research impact is defined by the Economic and Social Research Council (ESRC) as the demonstrable contribution that excellent research makes to society and the economy. Put simply, it’s how research benefits society and the economy.

Though usage metrics and citations are key performance indicators for an article and play a part in helping your work to be seen, research impact is not solely defined by citation numbers, usage figures or social media engagement.

Creating research impact means getting your work into the hands of those who can use it to contribute to making the world a better place.

In that sense, there are many ways to categorize research impact, and these factors often overlap.

Different Types of Impact: Scientific, Social, Economic, and More

The 2012 working group report from the European Science Foundation outlines the following main impact categories:

Scientific Impact

Contributions to the subsequent progress of knowledge, the formation of disciplines, training and capacity building.

Technological impact

Contributions to the creation of product, process and service innovations.

Economic Impact

Contributions to the sale price of products, a firm’s costs and revenues (micro level), and economic returns either through economic growth or productivity growth (macro level).

Social Impact

Contributions to community welfare, quality of life, behavior, practices and activities of people and groups.

Political Impact

Contributions to how policy makers act and how policies are constructed and to political stability.

Environmental Impact

Contributions to the management of the environment, for example natural resources, environmental pollution, climate and meteorology.

Health Impact

Contributions to public health, life expectancy, prevention of illnesses and quality of life.

Cultural Impact

Contributions to understanding of ideas and reality, values and beliefs.

Training Impact

Contributions to curricula, pedagogical tools, qualifications.

From Research to Impact: Planning for Success

Impact isn’t something that should be thought about at the end of your research or after publication. From the start of your research project and throughout the research process, ask yourself: what impact could this have? Reflecting on this question and getting very detailed in your answer will provide you with focus and motivation.

It will also influence the decisions you make, enabling you to report on your impact more effectively at the end of your project. Considering research impact upfront will:

• Influence who you collaborate with
• Help identify key stakeholders such as policymakers, to inform the research and the progress made
• Make decisions based on the benefits they could have to society
• Facilitate easier reporting of your research impact by incorporating early considerations and direction into the process.