In the context of two summer courses (a science methods course and a geology course), the authors worked with 40 elementary and high school teachers enrolled in Brooklyn College's M.S.E. programs in elementary education or secondary science education. They were involved in different ways, in the teaching of these courses, the organization of a summer institute and other events for educators at the American Museum of Natural History in New York City, and the assessment of project impact on teacher participants and their classrooms. Two of them taught these courses, one represented the American Museum of Natural History and liased with the College as director of professional development at the Museum, while the other worked on assessing project impact by interviewing teacher participants to gain insight into their thinking and practice. (Contains 13 references.) (SAH)