Based on a nationally representative probability sample of U.S. public high school biology teachers. A total of 926 teachers completed questionnaires between March 1 and May 5 of 2007. Teachers responded to 86 questions pertaining to their educational backgrounds, teaching practices, and personal attitudes. Focused on respondents' approach to teaching evolution and creationism in the classroom. Teachers' personal views and understanding of evolution were examined, as well as potential outside influences on their teaching, such as parents, school board members, and religious leaders.