Not sure if I am saying the obvious thing, but I think the teacher should have a larger database of questions, and choose the question for the test randomly. Not necessarily in a way “here are 100 questions, choose 10 of them”, but if the class consists of two equally important parts, it should be “here are 50 questions for the first part, 50 questions for the second part, choose 5 and 5″. Even within each part, you could choose e.g. 2 easy questions, 2 medium-hard questions, and 1 hard question. If some questions are central to the lesson, you can make them appear on the test with certainty. On the other hand, if there are many non-central, exotic questions, you can make the test always contain exactly 1 exotic question, even if you have 100 possible exotic questions in the database.
Using this system, anytime a student asks “will this be on exam?”, you can answer “with certain probability, yes”. More central questions will have higher probability, different tests will be relatively balanced, but you also need to learn the exotic questions if you want to have to achieve 100% score.
Not sure if I am saying the obvious thing, but I think the teacher should have a larger database of questions, and choose the question for the test randomly. Not necessarily in a way “here are 100 questions, choose 10 of them”, but if the class consists of two equally important parts, it should be “here are 50 questions for the first part, 50 questions for the second part, choose 5 and 5″. Even within each part, you could choose e.g. 2 easy questions, 2 medium-hard questions, and 1 hard question. If some questions are central to the lesson, you can make them appear on the test with certainty. On the other hand, if there are many non-central, exotic questions, you can make the test always contain exactly 1 exotic question, even if you have 100 possible exotic questions in the database.
Using this system, anytime a student asks “will this be on exam?”, you can answer “with certain probability, yes”. More central questions will have higher probability, different tests will be relatively balanced, but you also need to learn the exotic questions if you want to have to achieve 100% score.