The appropriate level of instructional guidance for students to acquire a deep understanding of the disciplinary core ideas, crosscutting concepts, and science and engineering practices outlined in the Next Generation Science Standards remains ambiguous. To shed light on this important topic, we tested two distinct science programs in a cluster randomized controlled trial involving 11 second-grade classrooms and 185 students. Holding constant content, dosage, and professional development, findings favored the program that provided greater levels of instructional guidance on all three science measures (g = 0.19, 0.21, 0.40). In addition, differential response analyses revealed that students with lower initial scores made significantly greater gains on a distal science measure in classrooms that implemented the program with more instructional guidance. Last, exploratory correlations between teacher-level instructional guidance and student outcomes suggested positive associations between guidance levels and outcome gains. Implications for designing and delivering science instruction to meet diverse student needs are discussed.
Gersib et al. (Mon,) studied this question.