Impact factors measure influence, not quality

Impact factors get brought up sometimes in scientific debates, but many people are not familiar with what they mean. Here are a few basics that help make sense of what a journal impact factor can and cannot tell you.

First, some key terms:

• Journal: A journal is a publication that regularly releases scientific articles throughout the year, such as original research. There are thousands of different science journals, some of the most popular are Nature, Science, Cell, and The New England Journal of Medicine (7). 
• Article: A scientific article is a piece of research that is usually published in a peer-reviewed journal. It explains the study’s question, methods, results, and conclusions so other scientists can evaluate the work, critique it, repeat it, or build on it (8,9).

A journal impact factor measures the journal influence (average citations per year). It doesn’t tell you about the influence (or trustworthiness) of a specific article. So, if you want to check whether a study is solid, look at the science itself, not the impact factor.