Pick an event that will result in the same outcome for everyone, such as whether it will rain next Saturday. Ask 10 people to assess the probability of that event, and note the variability in their responses. (Don’t let them hear each other’s answers, and make sure you don’t pick something that would have 0 or 1 as a common response.) At the same time, ask them the probability of getting a heart when a card is randomly chosen from a fair deck of cards. Compare the variability in responses for the two questions, and explain why one is more variable than the other.