One way to insure this deep processing is for learners to collaborate with other learners in solving problems or doing complex tasks. Another learning event that facilitates deep processing is when learners go public with their knowledge in an effort to critique other learners or to defend their work when it is critiqued by other learners.
These points make me recall my experience with exchange classes two years ago. Education at the Dutch university where I studied was centred around the concept of problem-based learning (PBL). Lectures were actually not mandatory. Tutorials, on the other hand, were. We met in groups of around 20 two times a week and worked through reflection and application questions together while supervised by a grad student. We also selected one or two people for each class to be discussion leaders or facilitators. They kept track of time, made sure we did not go off on a tangent, and posed additional questions to the group. The purpose behind such an interactive approach was to promote collective and individual critical thinking as well as connection with peers. It was quite difficult to adjust to, at first, because I was so used to a more passive didactic method. However, once I have discovered the benefits of consistent constructive feedback from classmates, I felt that discussion was often more effective than lecturing when it came to retaining information because it pushed me to actively participate in making course material meaningful.