Science-Metrix was commissioned by SRI International, on behalf of the National Science Foundation, to develop measures and indicators of research and patent activity using bibliometrics and patent data for inclusion in the Science and Engineering Indicators (SEI) 2018. This technical document details the various steps taken to implement the databases, clean and standardize the data, and produce statistics. 

Science-Metrix produced the bibliometric indicators for SEI 2018 using an in-house implementation of the Scopus database that had been carefully conditioned for the production of large-scale comparative bibliometric analyses. A similar approach using Scopus was also employed to produce indicators for SEI 2016. Prior to the 2016 edition, the bibliometric indicators included in editions of the SEI were computed based on data from the Science Citation Index (SCI) and the Social Sciences Citation Index (SSCI), two subsets of the Web of Science, which was at that time produced by Thomson Reuters. The differences between Scopus and the SCI and SSCI databases that were used for the previous editions of the SEI, and the implications of these differences for the production of bibliometric indicators for the SEI, were discussed comprehensively in a separate report.

For this project, the indicators were computed on science and engineering scientific publications; this includes publications on the natural sciences, the applied sciences, the medical sciences and the social sciences, but excludes the arts and humanities.

See the report here [PDF].

Note: This work was funded by the National Science Foundation’s (NSF) National Center for Science and Engineering Statistics (NCSES). Any opinions, findings, conclusions or recommendations expressed in this report do not necessarily reflect the views of NCSES or the NSF. The analysis for this research was conducted by SRI International on behalf of NSF’s NCSES under contract number NSFDACS1063289.

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