What is a Good Impact Factor?  

The Journal Impact Factor (also known as JIF or IF) is a crucial metric in the world of academic publishing, used to evaluate the influence and credibility of scientific journals. Developed in the 1970s by Eugene Garfield, the founder of the Institute for Scientific Information (ISI), the impact factor was originally intended to help university librarians decide which journals to purchase. Over time, it evolved into a widely recognised measure for assessing journal prestige and academic success.

Despite its widespread use, the relevance and interpretation of the JIF are often subjects of debate. While it can indicate a journal's reach and reputation, it does not measure the intrinsic quality of individual articles, nor does it account for differences in citation practices across disciplines. As the academic publishing landscape continues to evolve, thoughtful consideration of these limitations is essential.

What is an impact factor for journals? 

The Impact Factor is a widely recognised metric in academic publishing used to measure the influence and prestige of scientific journals. It reflects the average number of citations received by articles published in a journal over a specific time frame, typically two or five years. The IF provides a snapshot of how often the journal’s articles are referenced in other research, making it a key indicator of the journal's relevance and visibility in its field.

Clarivate Analytics calculates the IF as part of its JCR using the following formula for the two-year IF:

The five-year IF follows a similar formula but considers citations over five years instead of two. Citable articles typically include research articles and reviews but exclude editorials and letters.

So, to calculate a journals’ IF in 2023 you would need: 

• The number of citations the journal received in 2023
• The number of publications in the journal in 2022
• The number of publications in the journal in 2021

If the journal had 70,000 citations in 2023, 700 publications in 2022, and 900 publications in 2021, the calculation for the IF would look like this: 

In academia, Impact Factors are used as indicators of journal quality and influence. Journals with higher Impact Factors are generally perceived as publishing high-quality, impactful research that is frequently cited by other scholars.

This perception influences several decisions:

Author Decision-Making: Authors often prioritise submitting their work to journals with higher IFs to enhance their research's visibility and credibility. A publication in a high-impact journal can increase the likelihood of an article being cited by other researchers, which can, in turn, boost the author's professional reputation and impact metrics.

Institutional Evaluation: Universities and research organisations frequently consider the IF of journals when evaluating faculty for hiring, promotion, and tenure decisions. A strong publication record in high-impact journals may be seen as a marker of academic success and research excellence.

Funding and Grant Applications: Funding bodies may use the IF as a proxy for research quality when assessing grant applications. Researchers who publish in high-impact journals may be viewed as more likely to produce influential and high-quality work, making them stronger candidates for funding.

Library and Resource Management: University librarians use the IF to make informed decisions about journal subscriptions. Higher-impact journals are often prioritised for acquisition because they are seen as valuable resources for faculty and students.

Where to find impact factors? 

If you're looking for how to find the impact factor of a journal, several reliable sources are available:

1. Journal Citation Reports (JCR)

Clarivate Analytics produces the JCR annually, which is the primary source for Journal Impact Factors. JCR can be accessed through the Web of Science platform. 

2. Journal Websites

Many journals display their Impact Factor directly on their home pages or dedicated metrics pages. Look for sections labelled "About the Journal" or "Journal Metrics." 

3. University Libraries

Most university libraries provide access to impact factor databases, including the JCR. 

By leveraging these resources, researchers can identify the most impactful journals in their field and make informed decisions about where to submit their work or assess the influence of existing publications.

What is a good impact factor? 

Determining what is a good impact factor is not straightforward, as its significance can vary depending on the field of research and citation norms within that discipline. One key consideration is the range of impact factors for journals in a given field. However, general guidelines provide some insight:

Impact Factor Range

• Above 10 - Excellent - although unreachable in many disciplines 
• Between 3 and 10 - Good to very good, depending on the specific field.
• Between 1 and 3 - Average but respectable in many fields.
• Below 1 - Generally low but acceptable for niche or emerging fields.

Disciplinary Differences in Impact Factor Norms

Impact Factors are highly discipline-specific, with what constitutes a strong IF varying widely between fields. This variability is driven by differences in citation practices, the volume of publications, and research timelines across disciplines.

For example, leading journals in oncology tend to have exceptionally high IFs due to the rapid dissemination and broad citation of research findings. For example, CA: A Cancer Journal for Clinicians is a leading journal in oncology with an Impact Factor of 521.6 in 2023. 

However, some other disciplines have much lower Impact Factors, such as veterinary science. For instance, the Annual Review of Animal Biosciences, a leading journal in veterinary science, had an IF of 8.7 in 2023, making it highly respected in its domain.

Journals in the humanities and social sciences also tend to have lower Impact Factors. In some disciplines, such as history, an IF of 1 or higher can be considered strong.

How to Interpret a Good Impact Factor

Evaluating a JIF requires a thoughtful approach. While a high IF can be a sign of influence and quality, it’s important to interpret this metric in context and alongside other factors.

1. Compare Impact Factors Within the Same Field

Impact Factors vary significantly across disciplines, so always evaluate them within the context of your research area. For example, a strong IF in oncology is likely to be significantly higher, whereas in the humanities, an IF of 2 could be highly respected.

2. Look at Recent Trends

Impact Factors are calculated annually, so examining a journal’s performance over multiple years can provide valuable insights. Consistent growth in citations may indicate sustained influence and relevance in the field.

3. Consider Additional Metrics

Although the Impact Factor is a widely recognised measure, it shouldn’t be the sole determinant of a journal’s value. Other useful metrics include:

• CiteScore: Offers insights based on a four-year citation window.
• SCImago Journal Rank (SJR): Assesses journal influence by considering both the number and prestige of citations.
• h-index: Measures the productivity and citation impact of a journal or author.

Guidance for Early-Career Researchers

Choosing the right journal is a critical step for early-career researchers aiming to establish a strong publication record. While the Impact Factor shouldn't be the only criterion for selecting a journal, it serves as an excellent starting point when identifying reputable publications. High IFs can signal a journal's influence and the potential for a broader readership, but they must be balanced against other considerations.

Rather than focusing solely on journals with the highest IFs, prioritise those that align closely with your research goals, maintain strong editorial standards, and reach your target audience. A journal with a slightly lower IF may still be highly respected and provide a better platform for your work within a specialised field.

Are high-impact journals always better? 

While high-impact factor journals are often seen as prestigious, they are not always the best fit for every researcher or study. These journals typically prioritise widely cited research, but that doesn't necessarily make them the right platform for all types of scholarly work. In some fields, particularly emerging or niche areas, lower-impact journals can provide significant value by reaching a highly specialised audience or prioritising innovative research over citation counts.

Impact factor controversy 

The Impact Factor is a widely recognised measure of journal influence, but it is not without its controversies and limitations. Despite its utility in assessing journal prestige, its influence on academic publishing has sparked debates over fairness, research quality, and unintended consequences.

Limitations of the Impact Factor

• Skewed by highly cited articles: A small number of highly cited articles can disproportionately inflate a journal’s IF, giving an incomplete picture of its overall content quality.
• No measure of individual article quality: The IF reflects journal-level metrics, not the intrinsic value or impact of individual research articles. Groundbreaking studies may appear in lower-IF journals, while less impactful papers may be published in prestigious journals.
• Exclusion of newer journals: Journals need time to establish citation histories, making newer or niche journals disadvantaged by this metric.
• Influence of review articles: Review papers are frequently cited, which can artificially boost a journal's IF, skewing perceptions of its research impact.
• Limited societal or practical impact measurement: Research that leads to policy changes or real-world applications may not receive as many academic citations as theoretical studies, despite being highly influential outside the academic community.
• Open-access vs traditional publishing: Open-access journals have challenged traditional publishing models by rapidly gaining high-impact factors and reshaping perceptions of journal prestige. These journals often provide greater accessibility and visibility for research. One study in 2018 found that accounting for age and discipline, open-access articles receive 18% more citations than average. 

Beyond numbers: what wlse matters?

While the Impact Factor is a useful metric for assessing journal influence, it shouldn't be the sole criterion for evaluating a publication's value. 

Important factors to consider include:

• Scope and relevance: Ensure the journal's focus aligns with your research topic and goals.
• Editorial quality and peer-review: Look for journals with rigorous peer-review processes and strong editorial standards.
• Reputation in the field: Consider how well-respected the journal is within your specific discipline.
• Audience reach: Evaluate whether the journal effectively reaches your target audience, including researchers, practitioners, or policymakers.
• Open-access availability: Open-access journals increase the visibility and accessibility of research, particularly in low-resource settings.
• Complementary metrics: Explore additional metrics, such as:
  
  • CiteScore: Measures citation impact over a broader time frame.
  • Altmetrics: Captures online engagement and societal impact.
  • h-Index: Evaluates long-term research influence.

Conclusion 

Determining what is a good impact factor for a journal is highly context-dependent. What is impressive in one field may be average in another, highlighting the importance of making comparisons within the same discipline. Researchers should approach Impact Factors critically, recognising their value as a starting point but not as the sole measure of a journal's influence. Incorporating additional metrics such as CiteScore, Altmetrics, and the h-index, alongside qualitative factors like editorial standards and audience reach, provides a more comprehensive evaluation. As the academic publishing landscape continues to evolve, so too will the ways we assess journal impact, encouraging a more nuanced and inclusive understanding of research influence.