This proposal provides for the enhancement of content knowledge and pedagogical skills of under-prepared teachers of physical science. Participants will include 24 high school teachers of physical science in Texas. The program will utilize the instruction of a team of experienced, highly successful high school physical science teachers who are officers of TTOPS (Texas Teachers Organization for Physical Science) in conjunction with a pair of university professors in physics and chemistry. The project includes three components. These components focus on a two-week series of summer institute workshops on the basic concepts taught in the high school physical science courses; a series of follow-up workshops during the academic year on supplementary topics; and visits to the school and classroom of the participants to provide assistance with the implementation, evaluation of the program and reinforcement. Cost sharing is equivalent to 25% of the NSF award.