What makes answering ConcepTests so difficult?
EM: Children start life full of curiosity, they are all scientists - people who ask, "Why, why, why?" all the time. At some point in their middle school years, or maybe earlier, I don't know exactly, their curiosity gets turned off. From that point on, rather than ask, "Why, why, why?" people concentrate on facts. They want to know the fact, or the answer, so that they can memorize it. So when faced with a conceptual question, instead of thinking, what you do in your brain is begin looking for a fact. You look to see if you have seen the answer to that question before, and if it's a good conceptual question you will not have seen the answer to that question before. So they are difficult because people are not used to seeing them.