1, calculation method
Calculation formula: if (k) = (NK-1+NK-2)/NK-1+NK-2.
Note: K refers to a certain year, Nk- 1+Nk-2 refers to the number of papers published in the previous year or two, and Nk- 1 and Nk-2 refers to the number of cited articles in K years.
Take the calculation of IF in 2004 as an example: if = (number of citations in 2003+number of citations in 2002)/(number of articles in 2003+number of articles in 2002)
2. Production
The impact factor was founded in the 1960' s, and its original purpose was to evaluate and select the journals with current contents.
At present, the impact factor generally refers to the journal citation report (JCR), which provides the citation data of journals worldwide in the last year from 1975 every year, and gives the impact factor of each journal included in the database.
Application of journal impact factors;
The impact factors given by JCR and the above indicators play a very important role. Specifically, they have various practical values for the following types of personnel.
1. For librarians, they can make a document collection plan and budget and recommend excellent periodicals to readers.
2. For the author (scientific researcher), you can find and determine the journals related to your major, determine the journals that contribute, and confirm the level of the journals that you have published papers.
3. For information researchers and analysts, they can track the development trend of bibliometrics, study the citation mode between disciplines and within disciplines, study the knowledge of academic paper production, and study the development trend of professional disciplines.