Learning is an active process. I believe that the act of developing understand requires the learner to take external data and stimulus, wrestle with it, and build an individual understanding of the content at hand. In my courses I attempt to provide the necessary resources and environment for students to actively engage with course materials an construct an understanding of the subject.
Usually this intellectual wrestling match takes place in small group settings. As I find when your are at fisticuffs with the universe it's handy to bring backup.
Here are a few examples out the challenges I provide students to get the constructive combat of the mind rolling.