This study focuses on conditions that improve reading comprehension at grade 7th. We analyze the impact of the "Lirécrire" program, and related treatment integrity, on student performance. "Lirécrire" program should improve students' reading comprehension, and follow-up sessions should lead to greater instructional change, then improve learning. Nineteen schools were randomly assigned to one of two experimental conditions (with or without follow-up for teachers) or to the "control" group. Reading comprehension was measured pre- and posttest and treatment integrity through intensity and conformity. Students benefiting from the program outperformed students in the "control" group, with an additional effect of intensity.