This study explores the influence of mentor teachers in the meanings and practices that two elementary preservice teachers adopted about eliciting and using student ideas, while learning to teach science in the university science methods course and in the field placement classroom. Prior research on teacher development has shown that the high-leverage practice of eliciting and using student ideas can support preservice teachers in thinking about common problems of practice. I used four core problems of practice to examine the meanings and practices that preservice teachers adopted in eliciting and using student ideas as they planned, enacted and reflected on methods course assignments in the field placement classroom. Using sociocultural and situative perspectives on learning, I identified two factors that influenced the sense that preservice teachers constructed and the practices that they adopted about eliciting and using student ideas. These factors were mentor teacher's perspectives on learning and goals for student learning. I also examined three mechanisms by which mentor teacher's perspectives and goals influenced preservice teacher meanings and practices about eliciting and using student ideas in instruction, including mentor teacher's classroom practice, the nature and foci of mentor teacher and preservice teacher conversations and mentor teacher's use of preservice teachers' ideas in their conversations about instruction. The results suggest that preservice teachers come to make sense of and use student ideas in their instruction in ways that closely align with those of their mentors. They also indicate that preservice teachers' integration of experiences from different learning-to-teach contexts in making sense of student ideas may be related to the degree of alignment between mentor teachers' perspectives and goals and the perspectives and goals of the science methods course.