BBN Systems and Technologies will conduct a three-and-one- half-year program to develop and assess a comprehensive teacher enhancement program to foster the strategies, art, and practice of mathematical inquiry teaching in middle school mathematics classrooms. The program employs interactive computer software and video technology as key instructional tools for fostering inquiry learning and teaching skills. The program will comprise four graduate- level courses, two of which, Reasoning About Data and Mathematical Exploration and Experiment, were developed in a recently completed teacher enhancement grant. The two new courses, Animated Geometry and Interactive Algebra, will draw extensively on computer activities for supporting inquiry teaching. The courses will be field-tested at the University of Massachusetts, Boston; Lesley College, Cambridge; and the Educational Collaborative. Careful documentation of the extent to which teachers change as a result of these courses will be undertaken. The courses will be endorsed by the Massachusetts Department of Education and disseminated statewide by the Massachusetts Corporation for Educational Telecommunications. National dissemination will be instantiated through pre-conference workshops of relevant organizational meetings such as NCTM or AERA. Over 240 middle school teachers will be involved in the development and piloting of these courses. Logo Computer Systems, Key Curriculum Press, EDCO, MCET and BBN cost-sharing accounts for 7% of the NSF budget. Developing teacher enhancement materials which creatively make use of the latest technology is indeed desirable. BBN produces products that are at the cutting edge of technology. And the Massachusetts Corporation for Educational Telecommunications provides and excellent avenue for dissemination of the course materials so developed.