I used to think I was too cool and progressive to give quizzes. But a quiz tells you whether students are learning what you think you are teaching them, quickly and precisely. It’s a perfect data-collection tool: If students learned what you wanted them to learn, they will answer the questions correctly. If they haven’t, they won’t, allowing you to provide targeted help to specific students based on which questions they get wrong.
The only caveat is that you shouldn’t grade the quiz, because attaching a grade to a quiz ruins your data.
Think of it this way: When you give a quiz, you’re basically operating as a scientist conducting an experiment. You are testing the hypothesis, “These students learned what I spent all week teaching them.”
But if you grade students on how they perform, it ruins your data about what they actually learned. It’s like a scientist telling their test subjects, “Take this medication, and if you get the results I’m hoping to see, I’ll give you a hundred bucks.” That study is likely to achieve gratifying results for the scientist, but the results won’t be reliable.
As educators, we normally think of quizzes less as data-collection tools than as a means of motivating students to do their assigned work. The problem with this is that if a quiz is a motivational tool, it ceases to be useful as data. In economics this problem is known as Goodhart’s law (after Charles Goodhart), which states, “When a measure becomes a target, it ceases to be a good measure.”
So here’s my advice: When you give a quiz, just don’t put the results in the gradebook. This will help you find out what they know, rather than just showing what they studied for. In fact, tell them you don’t even want them to study for the quiz, because you are trying to find out what they know, not just what they crammed into their short-term memory last night and will forget once they finish the quiz.
