Generally speaking, the impact factor of journals is higher when it is greater than 2, higher when it is greater than 1, and lower when it is less than 0.5.

Impact factor (IF) is the data in Journal Citation Report (JCR) published by Thomson Reuters.

That is, the total number of cited papers published by a journal in the first two years of the reporting year (JCR year) divided by the total number of papers published by the journal in these two years. This is an internationally accepted periodical evaluation index.

Knowledge expansion

Impact factor refers to the number and type of citations of documents, and is an important indicator to measure the academic value and influence of documents. Specifically, the impact factor is the number of times a paper is cited in a specific time period divided by the total number of papers in that time period. The higher the value, the greater the academic value and influence of this document.

The calculation of impact factors needs to consider many factors, including citation times, impact factors of cited journals, citation time and so on. Among them, the number of citations is the most basic factor, and it is also an important part in the calculation of influencing factors.

Impact factors are widely used, especially in academia and publishing. In academia, impact factors are used to evaluate a scientist's academic achievements and contributions, and also to evaluate the academic level and quality of an academic journal. In the publishing industry, impact factors are used to evaluate the influence and value of a journal, and also to evaluate the academic value and influence of a paper.

However, these factors also have some problems and limitations. First of all, the impact factor is only a relative value, which cannot fully represent the academic value and influence of a document.

Secondly, there are many uncertainties and errors in the calculation of impact factors, such as inaccurate statistics of citation times, differences between self-citation and other citations, and so on. Finally, the impact factors are easy to be manipulated and used, such as improving the impact factors through false references and deliberately delaying publication.

Therefore, when evaluating the academic value and influence of a document, we can't just rely on the index of influence factors. Other factors need to be considered comprehensively, such as the innovation of the paper, the scientific and rigorous research methods, the reliability of the research results and so on. At the same time, it is necessary to combine other evaluation indicators for comprehensive evaluation, such as academic evaluation and reader feedback.

Generally speaking, the impact factor is an important evaluation index, but we should pay attention to its limitations and existing problems when using it. Only on the basis of comprehensive consideration of various factors can we accurately evaluate the academic value and influence of a document.