This paper reports on a part of a study of factors that contribute to science anxiety and science teaching self-efficacy among preservice primary and early childhood teachers. The experience and beliefs of primary and early childhood preservice teachers at an Australian University were explored in an ethnographic research tradition. In all, 366 students from four cohorts were studied. Two of the cohorts were undertaking a content oriented Science Foundations course that focused on matter and energy concepts. A third cohort undertook a Science Curriculum course that concentrated on science teaching methods, and the fourth cohort represented a smaller group of post-baccalaureate students who completed a combined content-methods course. The salient outcomes revealed that personal science teaching self-efficacy was associated with negative high school experiences and could be improved in situations where individual students experienced support and an appropriate learning environment. Outcome expectancy also could be improved through experiences in which students successfully implemented teaching programs to children. Analysis of qualitative data revealed interesting contrasts between students. A series of assertions about the causative factors that may influence the development of students' sense of self-efficacy were derived from an analysis of the data. Contains 46 references. (Author/LZ)