Impact factor (IF) is a data in the journal citation report (JCR) produced by Thomson Reuters, that is, the total number of citations of 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. The impact factors of periodicals fluctuate at a certain level every year.

The impact factor has become a general index of periodical evaluation in the world. It is not only an index to measure the usefulness and exhibition of periodicals, but also an important index to measure the academic level of periodicals and even the quality of papers.

In order to make it convenient for researchers to inquire about journal impact factors and publish articles in a targeted way, I specially collected the impact factors of 1 1 ~ 2016 JCR journals, among which11,834 journals, and selected 53 common journals in the information field for brief analysis.

The following 53 common periodicals are divided into three echelons, and the influencing factors and trend analysis over the years are given.

The first echelon [refers to veteran leaders]

7 journals with impact factors ≥20 (few journals with scores of about 20, but unfortunately 20 16, Natural Genetics dropped below 30). NBT and science have always been responsible for quality, and the shadow of influence has been rising steadily in recent years. Natural Genetics, as a heavy journal in genetics, has a downward trend in influencing factors in recent years. Perhaps the development of sequencing technology leads to too many similar articles, so it is more important to deeply mine the sequencing data today.

second echelon

24 journals, with an impact factor of 5~ 15. Journals in this range have more potential. Among them, the most powerful is cell research, and after five years, the influencing factors almost doubled. In addition, the performance of natural communication and nucleic acid research is also quite eye-catching, especially NC, 2065,438+06 has exceeded 65,438+02 points. The most unexpected is the classic journal Molecular Biology and Evolution, which went straight to 6 in 20 16, and fell to half compared with 20 15.

the third echelon

There are 22 journals with impact factors ranging from 2 to 5. It seems more difficult for journals with low scores to maintain the influencing factors, and six of them are declining year by year. In particular, PloS One shows a steady downward trend year by year, and it is less than 3 in 20 16 years, which is 6.8% lower than that in 20 1 1 year. Although the molecular biology of BMC increased a little at 20 14 and 20 15, it decreased compared with 20 16.