What is Journal Impact Factor and How it is calculated?
TLDRThe video script explains the concept of impact factor, a metric used to gauge a journal's significance in its field. It is calculated based on the average yearly citations received by articles published in the journal over the preceding two years. The script provides a formula and examples to illustrate how impact factor is determined. It also discusses limitations, such as self-citations and the lack of differentiation between positive and negative citations. The video promises to cover alternative quality indicators like Eigenfactor, Article Influence, and the h-index in a future episode.
Takeaways
- 📚 Impact Factor is a measure of the importance of a journal to its field, based on the yearly average number of citations to articles published in the journal from the last two years.
- 🔢 It indicates the average number of times each article published in a journal is cited over the next two years after its publication.
- 📈 An index journal is one that is indexed in a database like Web of Science, and an impact factor of 2 means an average of two citations per article.
- 📉 The impact factor for a particular year, such as 2019, is calculated by dividing the total citations in that year by the total number of papers published in the two preceding years.
- 🌰 An example given was calculating the impact factor of the Journal of Contemporary Research in Education for 2019, which resulted in an impact factor of 2.40.
- 🤔 The impact factor can be influenced by self-citations and the tendency of some editors to encourage authors to cite within the journal to increase its impact factor.
- 📉 Some disciplines tend to cite more than others, which can skew the impact factor as a measure of a journal's importance.
- 🚫 The impact factor does not account for negative citations, where papers may be cited critically or to point out flaws.
- 📉 Other quality indicators exist, such as Eigenfactor, Article Influence, and the h-index, which can provide a more nuanced view of a journal's impact.
- 🛠 Indexing agencies like Web of Science and Scopus provide these additional quality indicators for each journal.
- 📅 The impact factor is calculated each year and can vary, reflecting changes in citation patterns and journal performance.
Q & A
What is an impact factor?
-An impact factor is a measure reflecting the average number of citations to articles published in a journal over the next two years after their publication. It is used as an indicator of the importance of a journal to its field.
How is the impact factor calculated?
-The impact factor is calculated by dividing the total number of citations a journal received in a particular year by the total number of articles published in that journal in the previous two years.
What does an impact factor of 2 mean for a journal?
-A journal with an impact factor of 2 means that, on average, each article published in that journal receives two citations.
Can you provide an example of how to calculate the impact factor for a journal?
-Yes, for instance, if a journal published 20 articles in 2017 and 30 in 2018, and received 80 citations for 2017's articles and 40 for 2018's articles in 2019, the impact factor for 2019 would be (80+40)/50 = 2.40.
What are the limitations of using the impact factor as a measure of a journal's importance?
-Limitations include the influence of self-citations, the tendency of different disciplines to cite more or less, and the fact that it does not account for the context or quality of citations (i.e., whether they are positive or negative).
Why might some editors encourage authors to cite papers from their own journal?
-Some editors may encourage this practice to increase the journal's impact factor, as more citations generally lead to a higher impact factor.
What are some alternative quality indicators to the impact factor?
-Alternative quality indicators include Eigenfactor, Article Influence, and the h-index, among others.
Which indexing agencies provide quality indicators for journals?
-Indexing agencies such as Web of Science and Scopus provide quality indicators for each journal.
How might negative citations affect the impact factor?
-Negative citations, which could occur when a paper is criticized or refuted, still count towards the impact factor, potentially skewing the measure of a journal's influence.
What does an impact factor of three signify for a journal?
-An impact factor of three indicates that, on average, articles published in the journal in the previous two years were cited three times in the current year.
How might the impact factor of a journal change from year to year?
-The impact factor can change each year based on the fluctuation in the number of citations received and the number of articles published, leading to different impact factors annually.
Outlines
📈 Understanding Impact Factor and Its Calculation
This paragraph explains the concept of impact factor as a measure of a journal's significance within its field. It is calculated based on the average number of citations that articles published in the journal receive over a two-year period. The script provides a clear formula for calculating impact factor, which is the total citations in the current year divided by the total number of articles published in the previous two years. An example is given to illustrate the calculation process, showing how the impact factor can indicate the average number of times each article is cited. The paragraph also touches on the implications of a higher impact factor for editors and authors.
🔍 Limitations and Alternatives to Impact Factor
The second paragraph delves into the limitations and criticisms of using impact factor as a sole metric for journal quality. It mentions that self-citations can skew the impact factor, and the pressure on authors to cite within the same journal to inflate its impact factor. The paragraph also points out that impact factor does not account for the context or quality of citations, including negative citations which can also contribute to the total count. As an alternative, the script introduces other quality indicators such as the Eigenfactor, Article Influence, and the h-index, among others, and mentions that indexing agencies like Web of Science and Scopus provide these metrics. The speaker promises to explain these indicators in more detail in a subsequent video.
Mindmap
Keywords
💡Impact Factor
💡Citations
💡Journal Ranking
💡Index Journal
💡Yearly Average
💡Self-Citations
💡Disciplinary Differences
💡Negative Citations
💡Quality Indicators
💡Indexing Agency
Highlights
Impact factor is a measure of the importance of a journal to its field.
It's based on the yearly average number of citations to articles published in the journal from the last two years.
Impact factor indicates how many times each article published in a journal is cited over the next two years.
Index journals are those indexed in databases like the Web of Science.
A journal impact factor of 2 means it receives on average two citations per article.
The impact factor for 2019 is calculated as the total citations in 2019 divided by the total papers published in 2017 and 2018.
Impact factor is a ratio or average number of citations per article over two years.
An example calculation: Journal of Contemporary Research in Education had 20 articles in 2017 and 30 in 2018.
In 2019, articles from 2017 were cited 80 times, and articles from 2018 were cited 40 times.
Total articles published in 2017 and 2018 were 50, and total citations in 2019 were 120.
The impact factor for 2019 is calculated as 120 citations divided by 50 articles, resulting in 2.40.
An impact factor of 2.40 means each paper is cited 2.4 times on average.
Editors may encourage authors to cite papers from the same journal to increase the impact factor.
The more citations a journal has, the higher its impact factor.
Self-citations may influence the impact factor calculation.
Disciplines that cite more frequently can have a higher impact factor.
Impact factor does not account for negative citations, which is a significant limitation.
Other quality indicators like Eigenfactor, Article Influence, and h-index are alternatives to impact factor.
Indexing agencies like Web of Science and Scopus provide these quality indicators for journals.
Upcoming video will explain how to calculate and understand these general quality indicators.
Transcripts
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