BackgroundThe Transparency and Openness Promotion (TOP) Guidelines describe modular standards that journals can adopt to promote open science. The TOP Factor is a metric to describe the extent to which journals have adopted the TOP Guidelines in their policies. Systematic methods and rating instruments are needed to calculate the TOP Factor. Moreover, implementation of these open science policies depends on journal procedures and practices, for which TOP provides no standards or rating instruments.MethodsWe describe a process for assessing journal policies, procedures, and practices according to the TOP Guidelines. We developed this process as part of the Transparency of Research Underpinning Social Intervention Tiers (TRUST) Initiative to advance open science in the social intervention research ecosystem. We also provide new instruments for rating journal instructions to authors (policies), manuscript submission systems (procedures), and published articles (practices) according to standards in the TOP Guidelines. In addition, we describe how to determine the TOP Factor score for a journal, calculate reliability of journal ratings, and assess coherence among a journal’s policies, procedures, and practices. As a demonstration of this process, we describe a protocol for studying approximately 345 influential journals that have published research used to inform evidence-based policy.DiscussionThe TRUST Process includes systematic methods and rating instruments for assessing and facilitating implementation of the TOP Guidelines by journals across disciplines. Our study of journals publishing influential social intervention research will provide a comprehensive account of whether these journals have policies, procedures, and practices that are consistent with standards for open science and thereby facilitate the publication of trustworthy findings to inform evidence-based policy. Through this demonstration, we expect to identify ways to refine the TOP Guidelines and the TOP Factor. Refinements could include: improving templates for adoption in journal instructions to authors, manuscript submission systems, and published articles; revising explanatory guidance intended to enhance the use, understanding, and dissemination of the TOP Guidelines; and clarifying the distinctions among different levels of implementation.Research materials are available on the Open Science Framework: https://osf.io/txyr3/.