A growing body of research confirms that active approaches to learning offer many advantages over traditional instructional methods, including improved retention of information, conceptual understanding, and problem-solving skills. Content coverage in active-learning courses can be facilitated through careful selection and design of activities that guide student learning. Importantly, activities should engage groups of students in cooperative questioning, problem solving, analytical reasoning, and critical thinking. Focused instruction and reflection on thinking and learning help students develop as intentional learners.