The University of Miami (UM) and the Miami-Dade County Public Schools (M-DCPS)examines and improves elementary school teachers’ knowledge, beliefs and practices involving their teaching of science to English language learners (or ELL students) within an environment that is becoming increasingly driven by high-stakes testing in science. The four major research and development areas are (1) teachers’ initial knowledge, beliefs, and practices; (2) professional development intervention; (3) policy contexts; and (4) improvement among teachers and their ELL students.