Science education reform literature is dominated by calls to improve the teaching and learning of science in order to meet the demands of diverse students in a highly technological society. This paper discusses the relationship between teacher beliefs and instructional practices, particularly with regard to science-technology-society (STS) instructional themes. The link between professional development and teacher beliefs is also explored. A model of teacher professional development, the Kansas Collaborative Research Network (KanCRN), is discussed. (Contains 21 references.) (WRM)