George Mason University will be designing, implementing, and evaluating the Sustaining Teachers' Effective Pedagogy (STEP) model which will collaborate with the Head Start Professional Development Team (PDT) to identify effective teaching strategies which promotes and sustains teacher effectiveness and enhances student outcomes. Specifically, the STEP model will give Head Start teachers and teaching assistants the knowledge, skills, and attitudes needed to provide effective instruction that responds to the children's diverse cultural and linguistic backgrounds. The STEP model is comprised of a five-day STEP Institute, ongoing Community of Learning and Practice Groups, and online group and mentor interactions. In Year 1, STEP and the Head Start PDT will collaborate to design and develop the modules, materials, and resources needed for implementation. In Year 2, the project will be implemented in Alexandria Head Start classrooms with 17 teachers in STEP groups and 17 teachers in control groups. In Year 3, the project will be replicated among Northern Virginia Head Start sites with 30 teachers in STEP and 30 teachers in control groups. Results are expected to show STEP allows Head Start teachers to strengthen their practices and effective teaching strategies, increase teachers' abilities to identify intentional and culturally responsive teaching, and improve teachers' quality of teaching and sustaining positive child outcomes.