Radio Days requires the scripting and performance of a radio play, complete with sound effects and ads. Sworn to Serve requires the creation of a historically plausible portfolio for a fictional feudal family. As with design tasks, the constraints are the key, and they will differ depending on the creative product and topic being worked on. Balanced against the constraints, a task of this type should invite creativity by being somewhat open-ended. There should be enough wiggle room in the assignment that a student or group of students will be able to leave a unique stamp on what you're asking them to do.
Some topics go hand in hand with controversy.
People disagree because of differences in their value systems, in what they accept as factually correct, in what they've been exposed to, or in what their ultimate goals are. In this imperfect world, it's useful to expose future adults to such differences and to give them practice as resolving them. Consensus building tasks attempt to do that. The essence of a consensus building task is the requirement that differing viewpoints be articulated, considered, and accomodated where possible. For better or worse, current events and recent history provide many opportunities for practice.