Educational research assumes reflection on teaching examples to have positive effects on pre-service teachers' professional development. The role of teaching quality in such examples is unclear, however. In a field experiment with a pre-post-design, we taught “planning self-controlled learning” to 83 undergraduate pre-service physical education teachers and assigned them to three conditions: they either reflected on good teaching or problematic teaching examples or they compared both types of examples. We found that the comparison of examples supported their instruction planning more than reflecting good or problematic teaching examples only. In addition, comparing examples changed the pre-service teachers' beliefs.