Several different schemes have been developed to rank journals. Most are based on the number of citations that articles in the journal receive in a time-limited framework. The schemes differ in the length of time given for the articles to collect citations, the scope of the articles considered in the analysis, and the degree to which citation patterns in different disciplines are factored in.
The Journal Impact Factor (JIF) is the best known of the journal ranking systems. It was originally developed by Eugene Garfield using the data in the Science Citation Index (now Web of Science). The JIF is calculated annually and is published in a subscription database that is not available at MCPHS, but you can usually find a journal's Impact Factor on its website or on the publisher's website. It is based on two years of citation data. The JIF does not correct for differences in citation patterns in disciplines and therefore is most meaningful when it is considered in relation to other journals in the same discipline.
Example: Springer's Pharmacology Journals showing Journal Impact Factors
