This multiple case study examines how teachers request students' use of their content knowledge and conceptual understandings from out-of-school experiences while reasoning about science concepts and the ways in which students perceive and respond to these requests. Three middle school teachers and a total of 57 middle school students participated in this study. The data collection involved classroom observations and multiple interviews with each of the teachers individually and with small groups of students. The findings indicate that the students appreciate the usefulness of making relevant connections between their in-school and out-of-school learning, but seldom do so during science lessons. We also found that teachers' attempts to facilitate these types of connections during classroom discourse events involved the use of analogies, examples, or questions. Finally, the findings also indicate that students often recognize teachers' requests but seldom relate to these requests in the way the teacher intends.