During the last decade, many states have tried to devise more robust and coherent instructional policies in an effort to make teaching and learning more thoughtful and demanding. As instructional policy has moved to the top of many state education agendas in the past 10-15 years, interest in the relationship between policy and practice has grown. This document reports on findings from a study that addresses these relationships. Data used in this study were collected from a 1994 survey of California elementary school teachers to probe the classroom effects of state efforts to reform mathematics teaching and learning. A rudimentary model of the relationship between policy and practice is developed. This report begins with a review of the California reform, describes the research approach, and discusses the major findings. Findings included: (1) learning opportunities varied among teachers; (2) certain types of learning opportunities influenced practice; (4) CLAS (California Learning Assessment System) tests had a limited influence on practice; (5) CLAS as learning opportunity had a wider influence on practice; and (6) certain teacher learning opportunities affected student achievement. (ASK)