One option is to look at a standards based report. You can look to see if there was an item (or standard, domain, item, etc) that, for example, that a majority of your students missed. You can look at the specific item and find out why the students didn't answer the question correctly (type of question, how it's asked, etc) and make decisions as to whether or not you need to reteach that skill or teach it in a different way. It's important that you are not judging this information based on one question. Sometimes it's best to look if students missed the same skill on several questions or just one.
