Quantitative analysis of journals is a way traditional peer review may be augmented to gain a more complete picture of a scholar's impact in his chosen field. Three measures can be used:
Knowing the impact or importance of the journal can help in decisions about where an author will choose to submit an article. Libraries and librarians also use journal rankings to make decisions about collection development.
One cannot meaningfully compare two journals in different disciplines using impact factors because impact factors vary among disciplines. For this reason, it is helpful to see how a journal ranks based on other journals in the subject category. First, find the journal to see what discipline or subject category/categories it falls within. Then find the total number of journals in the subject area. Subtract the ranking of the journal from the total number of journals and divide by the number of journals in the subject area minus 1. Thus you will find the percentile ranking.
n=number of journals in the subject category
n-rank/n-1 x 100 =percentile