The journal impact factor is a measure of the frequency with which the "average article" in a journal has been cited in a particular year. The impact factor will help you evaluate a journal's relative importance, especially when you compare it to others in the same field. The impact factor is calculated by dividing the number of current citations to articles published in the two previous years by the total number of articles published in the two previous years.

a simple ratio of citations and papers

A quantitative measure of the frequency with which the "average article" published in a given scholarly journal has been cited in a particular year or period, this is used in citation analysis

The hierarchical measurement of the ten levels of product placement from Background to Verbal plus, which serve as the base level metric to calculate the quality of a branded entertainment effort.