Impact Factor
Recognized by other titles such as Journal Influence, Citation Rate, and
Impact, this index was originally designed by Garfield to manage journals and
as an indicator for entering the collection in the Current Contents so that
high-value journals could be indexed in this collection. However, the index is
not applied to validate all research publications and their creators. Today,
this index is used in several different ways, such as ranking and evaluating
countries, universities, and scientists. One of the advantages of this index is
easy to access to the data required for the relevant calculations.
The term "impact factor" was first used
in 1963 to quantify publications in the citation index of science edited. The impact factor of journals is
considered as a scale and criterion of frequency and can be used to determine
the mean number of articles referenced in a journal over a specific duration. Nevertheless,
a two-year course is regarded for this assessment since according to the
experiences in this field, approximately 20% of the total references refer to
the publications of the past two years. Therefore, Garfield considered the
two-year period as an acceptable basis to measure the reference level of journals.
Impact factor of journals can be calculated
using the equation below:
