Cooper 11 introduces the notion of flow. As an example, a Norman door stops the pedestrian from doing whatever it is they are doing and forces them to think about how to open that particular door. In other words, a Norman door breaks flow, and that's precisely why a Norman door is annoying. It's not that we can't figure the door out (most of the time, anyway). It's that we're being forced to figure it out when the door should ideally escape our conscious notice entirely.
Cooper further describes a set of techniques around the notion of orchestration that can help the designer come up with an interface that induces flow.
Assignment: Choose an interface and analyze it for flow. Unlike the Norman door, your example should be software-related. You may need to restrict attention to a particular task on that interface.
You should mostly focus on witnesses, but you should also keep an eye out for counterexamples.