This paper discusses how assessment practices in higher education can improve or hinder learning. An example is given to illustrate some common educational practices that may be contributing to underpreparation and underperformance of students. Elements of effective learning environments that may better address underlying metacognitive issues are discussed. The principles of the Berkeley Evaluation & Assessment Research Assessment (BEAR) System are introduced, and their use to improve learning is described in the context of the UC Berkeley ChemQuery project.