true, there are some errors, but i thought it was a good resource. if you're suspicious about one of the answers, then do some reading or searching and try to find out what the correct answer might be. this will expose you to other material that you might not have studied otherwise. i did the 5 free tests then wanted the other 5 so i pretty much paid $22 for 5 tests. i definitely saw material on my actual DAT that was covered in datQvault 🙂