Before making up an exam, go over the kinds of information and skills emphasized in the course. The exam should be constructed accordingly. Students should be told in advance, preferably at the beginning of the quarter, what kinds of exams will be given in a course. Since some students may have access to old exams, if the course is a long-running one, it is probably fairer to give all students sample copies of at least one previous exam. If you are new to the course, you will also want to go over the old tests carefully and see both what was covered and how.
Frequent testing can enhance learning as well as provide information on student progress.
Unless you intend to discuss them in class, you should hand tests back at the end of a period in order to avoid students being preoccupied by them while you try to cover something else. Explicit directions and clearly stated questions are two key ingredients in a good exam. No matter how clearly you write these beforehand, however, you should still go over them with the students at the beginning of the actual test. If a student comes up and asks you privately about a question that looks as though it could be confusing to others, share your answer with the whole class. The placement of questions and answer spaces, or choices, on a page also needs consideration.