The purpose of document is to provide readers with the coding protocol that authors
used to code 22 mathematics intervention meta-analyses focused on participants with or
at-risk of disabilities. The author drafted this coding protocol based on the meta-analysis
quality indicators recommended by Talbott et al. (2018, pp. 248–249); specifically, the
author considered the variables presented in Table 1 of Talbott et al. and supplemented
the information so that the variables and definitions were specific to the purpose of this
systematic review. We coded each meta-analysis for 53 variables across eight categories,
including: Quality of Clear Research Questions, Quality of Eligibility Criteria, Quality
of Search Procedures, Quality of Screening Criteria, Quality of Coding Procedures, Quality
of Research Participants and Contexts, Quality of Data Analysis Plan, and Quality of Reporting
Results. The mean interrater reliability across all codes using this protocol was 87.8% (range
across categories = 74% –100%).