Hi Melanie,
The scoring algorithm on the GMAT is far more complicated than most people realize. The number of correct answers on a section is not the only factor in what determines your score. The algorithm factors in a number of variables, including the relative difficulty of the question (if you're expected to get it right or not), the position of the question, whether the question is active or experimental (there are questions in both the Quant and Verbal sections that do NOT count), if you don't answer questions at the end (they're marked as wrong AND penalized), as well as a few other things. As such, the number of correct answers is a mis-leading statistic.
When reviewing a CAT, it's more useful to focus on WHY you got questions wrong than to focus on the number of questions that you got wrong. If you made silly/little mistakes that can be easily fixed, then those fixes are the easiest way to improve your score (assuming that not all of the questions that you got wrong were experimental). Since you're never going to know which questions "count" and which are experimental, there's isn't much use in focusing on that idea.
GMAT assassins aren't born, they're made,
Rich
