This is a summary of the lab exercises (providing my answers and the ones provided by the TAs)
For POC, I'd say, just use the lab as a good reference and if you don't get something, just copy their argument or ask for examples. Sometimes some stuff doesn't make sense or feels really stupid to do.
(POC has a lot of moments where you "describe the obvious." You do that to figure out potential issues in design or other Comp Sci X Human related issues. Most of my semester was focused on design though.)