The authors explored two methods to promote prospective teachers' awareness of learner diversity and application of teaching principles using a problem-based learning environment. In Experiment 1, the authors examined the effects of presenting a conceptual framework about learners' individual and group differences either before or after instruction on teaching principles. In Experiment 2, the authors examined the effects of signaling issues of diversity within a set of worked-out classroom cases that were presented in either text or animated format.