It is, but how do you know the material is hard enough? If I teach history and have a finale exam with one question, “who was the first president of the United

It is, but how do you know the material is hard enough? If I teach history and have a finale exam with one question, “who was the first president of the United States?” then the students will all get A’s, but nobody would consider that a college level history test, and even if you made an A, there is no way to know that you mastered the subject. That’s a simplification, but in essence the issue at stake here.