This Chapter, "Knowing What To Do" talked more about certain limitations that can help us figure out what exactly we are doing. Norman related these "constraints" to switches for lights or electronics. It made complete sense when he discussed the problem with light switches. How can you effectively plan out where to out light switches for a 3 dimensional room on a 2 dimensional pad. That is why most people including myself find it difficult to figure out which switch controls which lights.
His new idea about making a 3 dimensional light switch panel seemed so much more functional, which made me wonder why no one else had thought of it. People don't think of it because designers sometimes look at the visual quality rather than it's usability. His new idea for the light switch panel was a 3 dimensional panel set up to replicate the room in which the lights were. Each light switch was placed in correspondence of where the light actually was in the room. This invention may not be as sleek and visually appealing, but it had amazing usability, which can be more important when you want to turn the light on. I hope that his new idea for light switch panels can become more dominant in the everyday world.