New techniques for active learning in large classes are being developed and implemented with increasing regularity, but methods for assessing student learning have not progressed with equal rapidity. Machine-scored exams are often a necessity, and these don't often probe the students' higher-order analytical or processing skills. Exams still form a central part of the students' grades, and so if the exams are not aligned with the active-learning methods used during class time, the incentive for student participation may be lost. Under the auspices of changes to our course initiated under STEMTEC (Science, Technology, Engineering and Mathematics Teacher Education Collaborative) we have incorporated cooperative and active learning into exams. We use a two-stage examination format, loosely based on the "Pyramid Exam" implemented in calculus courses at Smith College. In the first stage, students take a traditional machine-scored multiple-choice exam during the first half-hour of the exam period. They hand in their answer sheets, and then they take the entire exam a second time working collaboratively. This gives the students an opportunity to analyze their answers, to discuss their reasoning with their peers, and to come to a better understanding of the science behind the questions. We also give them additional questions on the collaborative portion of the exam that are more involved and that are frequently based upon collaborative exercises done previously during class. Grades for the exams are a combination of the individual and collaborative components (usually 75%-25%).

Our data show that this exam format has a positive impact upon student performance in the course. The exam itself becomes an active-learning exercise where students review and process the information and principles they have studied. Comparisons with previous iterations of the course show that students are more engaged in the course during class time and score higher on the individual portions of the exams. Student surveys also indicate that they have learned more owing to the exam format. The two-stage collaborative exam is a simple and effective technique for changing the dynamics of large classes.