The Source Normalized Impact Paper (SNIP) was created by Professor Henk Moed at the Centre for Science and Technology Studies (CTWS), University of Leiden. It measures contextual citation impact by weighting citations based on the total number of citations in a subject field, using Scopus data.
This indicator shows the impact of citations of publications from a particular journal in relation to the total number of citations within a scientific category. It is calculated by dividing the average number of citations in a given year for publications from the last three years (journal's impact per publication (IPP)) by the DCP (database citation potential) index, which, in simple terms, is based on the average number of citations for publications from the last three years in a given category. It should be noted that it has a different methodology from the CiteScore, as its calculation takes into account only three types of documents: article, conference paper, and review.