For every What Works Clearinghouse (WWC) review, reviewers will be asked to complete a Study Review Guide (SRG). A completed SRG should be a reviewer's independent assessment of the study, relative to the criteria specified in the review protocol and the WWC Procedures and Standards Handbook (Handbook). At the end of the review process, a Master SRG (MRG) will represent the final assessment of the study and provide a record for the WWC, as well as serve as a key input in producing reports. This document provides step-by-step instructions on how to complete the Study Review Guide (SRG, Version S3, V1) for randomized controlled trials (RCTs) and quasiexperimental designs (QEDs). This guide is intended to be used by individuals trained and certified in the WWC review standards and procedures and in conjunction with the WWC Procedures and Standards Handbook.