From Journal Citation Reports, the Immediacy Index divides the number of citations to a journal in a given year by the number of articles published by the journal in that year. It is intended to measure how quickly articles in a journal are cited, and may be most relevant in cutting edge disciplines. 

The Immediacy Index disadvantages infrequently published journals since there is less of the year available to get cited. 

1. Open Journal Citation Reports.

2. Enter your journal title. As you type a suggested title may be displayed; select it and complete the search.

3. Scroll down to the very bottom of the page, where you will see the immediacy index in the "Additional metrics" section.