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Bibliometrics and Altmetrics: Measuring the Impact of Knowledge

This guide includes information on which of the databases contain citation measures that can be used to gage either an author, article or journal impact.

Differences with Journal Impact Factors

The main differences between the indicators provided by CWTS Journal Indicators, in particular the RIP and SNIP indicators, and the journal impact factor (JIF) can be summarized as follows:

  • Based on Scopus (RIP and SNIP) vs. based on Web of Science (JIF).
  • Correction for field differences (SNIP) vs. no correction for field differences (RIP and JIF).
  • Three years of cited publications (RIP and SNIP) vs. two years of cited publications (JIF).
  • Citations from selected sources and selected document types only (RIP and SNIP) vs. citations from all sources and document types (JIF).
  • Citations to selected document types only (RIP and SNIP) vs. citations to all document types (JIF).

More information

Technical Details of CWTS Journal Indicators

SNIP is just one type of measure created by Moed and his team.

Look in this PDF for the descriptions of the types of data represented in the Centre for Science and Technology Studies (CWTS) Journal Indicators at Leiden University.

Example of a Source Normalized Impact per Paper (SNIP) Search

To compare journals in a specific subject field, follow the steps:

          1. Go to CWTS Journal Indicators web site.

          2. Click on the Indicators tab.

          3. Make your selections from the drop down menus. In this search, the SNIP Indicators for journals in Psychology are shown below.