In this paper, we examine the impact of three learning activities designed to foster more robust learning in a Genetics Cognitive Tutor module on pedigree analysis problem solving, in an experimental study. The three activities are (1) interleaved worked examples with student explanations; (2) enhanced feedback with tutor-provided explanations of problem solving steps; and (3) explicit scaffolding of the reasoning steps in this abductive process-of-elimination reasoning task. The study included four between-subject conditions, a baseline condition in which students exclusively solved standard problems, and three conditions in which students engaged in one of the new learning activities along with standard problem solving. The scaffolded-reasoning condition was most successful in fostering robust learning, as measured by transfer, retention, and preparation for future learning tests. The enhanced feedback condition, in contrast, yielded the poorest performance on the robust learning measures.