For almost two decades proponents of educational reform have advocated the use of standards-based education in maths and science classrooms for improving teacher practices, increasing student learning, and raising the quality of maths and science instruction. This study empirically examined the impact of specific standards-based teacher preparation and practices in secondary mathematics and science classrooms on student performance in maths and science. The study utilised an original data-driven P3 model, Preparation, Practice, and Performance, as the framework for the research design. Data obtained from over 400 classrooms in an urban US Mid-west public-school district (relative to teacher preparation, teacher practices, and student performance) were analysed using multiple regression analysis to determine which specific standards-based or non-standards-based practices are significant contributors to students' achievement. The results provide empirical evidence of the effectiveness of standards-based instruction in maths and science education and substantial support for the data-driven P3 model Preparation, Practice, and Performance as an effective framework for school districts grappling with reform concerns in maths and science education. (Contains 2 tables and 1 figure.)