I recommend not reviewing the wrong answers after testing on a chapter (whichever self test you are using). Instead, re-read the chapter, and concepts will start to jump out at you. Quite tedious but it does work. There is a small percentage of questions on the actual test that are also on the STS, however some questions will look similar but expect a completely different answer - that is why I am recommending you don't review the answers - your brain will play tricks on you. Tim Hall makes some very good recommendations.