Patrick,
WELCOME TO THE AWS WELDING FORUM!!
Very few people can tell you 'oh, that question is on Metallurgy' or 'that question was on welder qualification'. The questions are worded in such a way that many of them can qualify for a couple of different things and how the certification committee, via the computer, went through and decided which question fell into this or that category only God knows.
Analyzing the questions to study 'ONLY' the categories you 'think' you did poorly in is a major mistake. Go through the Sample Fundamentals book until you know it by heart. Better yet, go through the WIT book, The Welding Inspection Handbook, and any other material you may have until you are really familiar with all aspects of the welding industry. Trying to focus on a section you only missed 5 out of the 42 you can miss and still pass the exam is wrong thinking. I would be willing to bet you missed some from almost every category and if you study it all and pick up 1 or 2 here and there for a total of say 10 extra correct answers you should be good.
That is of course, assuming you were at least close to passing and don't need a complete redo of your goals for getting less than 50% on the exam.
He Is In Control, Have a Great Day, Brent