Promoting Acceleration of Comprehension and Content Through Text in High School Social Studies Classes

41 eleventh-grade US history classes (23 treatment), 14 teachers

Eleventh-graders enrolled in US History in US high schools

Within-teacher randomised efficacy trial extending PACT from grade 8 to grade 11, so it tests whether the middle-school pattern holds with older students studying the same US history content. Both arms got the same content from the same teachers; only the treatment arm used the PACT components. Same outcome battery as the eighth-grade trials: a researcher-developed content-acquisition test built from released state/AP items, a researcher-developed social studies reading comprehension measure, and an independent standardized general reading comprehension test. Delayed testing at 4 and 12 weeks. Read at ABSTRACT depth (paywalled), cross-checked against the developers' own narrative of the trial in Roberts et al. (2023), which reports the same figures; attrition, clustering adjustments and moderator detail have not been verified.

The grade-11 result is the grade-8 result again, which is what makes the pattern credible. Content acquisition: ES = 0.36 at posttest, 0.22 at 4 weeks, 0.24 at 12 weeks - a durable gain in US history knowledge that was still ~two-thirds of its original size three months later. And on BOTH comprehension measures - the content-area one and the general standardized one - there were no statistically significant effects at all. Five of the six PACT trials now say the same thing: content-rich history instruction teaches history, and does not teach reading.

Low. Classes randomised within teacher; genes balanced in expectation across arms.

A conceptual replication at a new grade level of Vaughn et al. (2013) and Vaughn et al. (2015), and it replicates the knowledge effect (0.36 vs 0.32) and the comprehension null. Internal to the developer team; PACT has never been independently evaluated.