This paper provides an examination of the foundations, efficacy, and effectiveness of a set of practices associated with improved social studies and history learning and literacy outcomes for middle grade students, including students with varying learning needs (e.g., English learners, students with disabilities). This approach, Promoting Adolescents' Comprehension of Text, has been the focus of multiple randomized controlled trials, including a large-scale effectiveness study. This paper has two foci: (a) to examine the evidence for the PACT intervention across settings, populations, and time and (b) to consider the design of these studies and the unit of randomization (i.e., within teacher or across school) to better understand why the typically expected differential effect sizes between efficacy and effectiveness studies were not evident.