Addendum to Protocol for Scoping Reviews of (1) Academic, (2) Societal and (3) Economic impacts of Open Science: PROTOCOL FOR GREY LITERATURE SEARCH AND INDEXING OF SOURCES,AND FOR SCREENING AND DATA CHARTING IN THE SYRF PLATFORM

As part of the literature search process described in the published protocol (Ross-Hellauer, Klebel and Pitelis 2022), we have conducted ascending and descending snowballing of peer-reviewed literature that was passed through to the data extraction phase, and we will conduct a search for relevant grey literature.In this addendum to our published protocol for this study, we describe the snowball search procedure and the subsequent sampling procedure for literature pertaining to academic, societal or economic impacts of Open Science. Then, we describe in greater detail the procedure for searching, archiving and screening grey literature. Finally, we describe our use of the Systematic Review Facility (SyRF)platformfor this second phase of the review process and the procedures we will use thereinfor the studies focused on academic and societal impact (not economic impact).