This three year project, sponsored by Montana State University, will provide an opportunity for 150 teachers, through an on-line computer network, to take six courses selected from a prior successful NSF program. These courses have been revised to conform to the requirements of the new delivery. Each year the course will be revised to increase its effectiveness. Teachers will be provided a text, a study guide and a bit of materials for hands-on activities. The final evaluation of the program will study the effectiveness of this approach in the development of teacher knowledge and the changes made in the classrooms and compare with on-site teacher enhancement programs. The matching fund provided by the University can constitute 15% of the NSF award.