This study investigates, through a cluster-randomized trial, the effectiveness of two approaches to increasing middle school students' science learning using a traditional science curriculum. Ninety schools were randomly assigned into one of three arms: (a) a treatment arm in which the textbook curriculum was modified based on four principles of…

This study used a cluster randomized controlled trial to investigate the effectiveness of two approaches to increasing middle school students' science learning when using an inquiry-based science curriculum. Eighty-nine schools, with 253 teachers and 20,591 students, were randomly assigned into one of three conditions: (a) a treatment condition in…

Four principles of cognitive science were used to make systematic revisions in middle school science instructional modules from two kinds of curriculum: one popular textbook series and one popular hands-on series (two modules each). Schools were randomly assigned to 1 of the 3 arms (cognitive science modifications with professional development,…

We explored whether existing curricula can be adapted to increase students' skills at comprehending and learning from diagrams using an intervention delivered by regular middle-school teachers in intact classrooms. Ninety-two teachers in three states implemented our modified materials over six curricular units from two publishers: "Holt"…