Q: What is the cumulative impact index of a journal?

The cumulative impact index of a journal is a long-term measure of its impact factor. Thus, while the impact factor is generally calculated for 2 years, the cumulative impact factor or cumulative impact factors can be calculated over a longer period, such as 5 or 10 years. This is explained in detail in an article by Eugene Garfield titled 'Impact of Cumulative Impact Factors.' However, the cumulative impact index of a journal is usually not mentioned on the journal website. The Journal Citation Reports (JCR) do not include this metric. Additionally, the criteria mentioned by the All India Council for Technical Education does not specify the number of years that have been taken into account while calculating the cumulative impact index. Therefore, there is really no clear way to figure out the cumulative impact index of a journal. One possible way to calculate it is to use the last 5 years as a baseline and calculate the impact factor yourself as follows:

However, we cannot be certain that this calculation meets the specifications of the council. Hence, it might be a good idea to write to the council and seek further clarifications if possible.

Recommended reading:

• The impact factor: for better or worse