Experiences in improving introductory physics labs

Holmes and Wieman reply: We are pleased to hear of other instructors working to provide students with authentic experimental physics experiences. We agree with Alwyn Eades that “confirmatory” or “verification” labs, an area we have studied, can be particularly problematic. Preliminary research results indicate that, unsurprisingly, students engage in more scientific behaviors in evaluation labs than in verification labs. However, it is not clear whether the outcome of an experiment needs to be unknown in general or simply unknown to the students. That is a subject for future study.