Although prescribed standards for science education are the basis for educational reform in virtually all states in the United States, these standards are often problematic. Indeed, an emphasis on prescribed standards often (1) frustrates and inhibits good teachers, (2) marginalizes many at-risk students, (3) produces curricula that ignore fundamental ideas in science (e.g., many states' standards do not mention the word "evolution"), and (4) do not enhance teaching and learning. It is teachers, not prescribed standards, who are the most important ingredient of science education.