The vision

On October 18th, new values for SNIP and SJR were published.

About Modified SNIP

Leiden University's Centre for Science & Technology Studies (CWTS) has introduced a number of modifications to the SNIP journal metric.

The aim of these modifications is to further improve the mechanism used by the SNIP metric to correct for differences in citation practices between scientific fields. In this way, the accuracy of comparisons of the citation impact of journals from different fields will increase. The modifications that have been made only affect the denominator of the SNIP metric which is responsible for the correction for field citation pattern differences.

The three most significant modifications to SNIP:

  • A different averaging procedure is used in the calculation of the denominator reducing the impact of outliers
  • A correction factor is introduced to ensure that citations from journals with low numbers of references are weighted properly
  • The new calculation results in a SNIP average score for all journals in Scopus to approximately equal one, making comparison of Journal scores easier

About Modified SJR
SCImago has introduced modifications to the SJR algorithm. The refined SJR, now called SJR2, recognizes the value of citations from closely related journals, compensates for an ever increasing volume of journals, and makes comparison easier with an average value equal to one.

Specific improvements to SJR include:

  • Take into account the more prestigious nature of citations that come from within or closely related fields
  • Overcome the tendency for prestige scores to diminish over time as the world-wide quantity of journals increases
  • Offer a more readily understandable scoring scale with an average of 1 for easy comparison

Download the new SNIP and SJR values on the 'values' page

About SNIP & SJR

The academic community has long been demanding more transparency, choice and accuracy in research assessment. Currently, the majority of academic output is evaluated based on a single ranking of journal impact. Editors want refined metrics that show them how their journal is performing in context and against their peers, and researchers need to make informed decisions in their publishing strategies. They also want this for free. Bibliometricians and research evaluators are under pressure to produce ever more accurate analyses of the research landscape. In response, bibliometricians have been exploring new methods to provide deeper insight. Within the field of journal evaluation, two of the most exciting are Source-Normalized Impact per Paper (SNIP) and SCImago Journal Rank (SJR).


  • Apply to nearly 18,000 journals, proceedings and book series.
  • Are refreshed twice a year to ensure currency.
  • Eliminate the risk of manipulation.
  • Correct for citation behavior and database coverage.
  • Provide multidimensional insights into journal performance.
  • Allow for a direct comparison of journals, independent of their subject classification.
  • Are publicly accessible and are integrated into Scopus Journal Analyzer.

Download the SNIP and SJR fact sheet (pdf) or click here to see the values