Approximately 700,000 college and university students enroll in introductory biology courses each year. The majority of these courses deliver the basic facts and terms of biology to large numbers of passive students. Few of these courses have learning scientific reasoning skills among their stated objectives. This project is developing a set of teaching tools and tests in biology centered around the primary learning objective of model-based reasoning (MBR), the central intellectual activity of professional biologists. The intellectual merit of the project lies in the development, evaluation, and dissemination of a set of methods and tools for teaching and testing model-based reasoning in college level introductory biology courses. An independent panel of experts, drawn from among professional biologists nationwide, is rating model-based reasoning questions. These expert ratings are compared with student performance in a classroom in which MBR problems are used for teaching and assessment. This study uses open-ended essays to investigate changes in students' descriptions of their reasoning process at several points during the course. Improvements in reasoning skills are being compared between students in MBR-based courses and traditional lecture-based instruction. A series of valid multiple-choice summative examinations designed specifically to assess model-based reasoning skills are also being developed. Model-based reasoning instruction has the potential for broad impact in introductory biology courses nationwide. It exploits the strengths of two technologies that are being widely adopted. The first is web based course support, and the second is the use of Classroom Communications Systems (personal response devices) in the lecture hall. In partnership with a major publisher, a teacher's guide and student study materials are being published.
