Fostering student teachers' confidence and competence to teach science in early childhood settings is a complex and challenging task for teacher educators situated in university classrooms. The research reported in this paper is based on an analysis of 3rd-year early childhood student teachers' assignments. The assignment required them to interview young children in order to find out what the children knew about a specified science topic. Three themes emerged from a constant comparison analysis. The first was the artificiality of the situation as constrained by the task. The second was the importance of sound subject knowledge in being able to ask questions of the children that were not misleading or difficult to answer. The third theme encompassed the difficulties associated with engaging young children in meaningful conversations. As a result of this analysis, the assignment task was modified to enable student teachers to work in more pedagogically appropriate and authentic ways.