3:

Impact factor and immediacy index

The impact factor of "Journal X" is calculated by "dividing the number of all current citations of source items published in Journal X during the previous two years by the number of articles Journal X published in these two years". That is, "it is a measure of the frequency with which the ‘average article' in a journal has been cited in a particular year", or the average "citation rate" of a journal's articles. The immediacy index of "Journal X" is calculated by "dividing the number of all current citations of current source items published in Journal X by the total number of articles Journal X published that year". That is, it is the average number of current articles in a specific journal that are cited during the year they were published. It is "a measure of how quickly the ‘average article' in a specific journal is cited", or a measure of relative "currency" of journal publications. ©MJA 1998 Back to article | Home | Issues | MJA shop | Terms of use | MJA Careers | More... | Contact | Topics | Search | RSS  mja.com.au | The Medical Journal of Australia   <URL: http://www.mja.com.au/> © 1998 Medical Journal of Australia. We appreciate your comments.