SUGGESTED ANSWER TO QUESTION 1-2

Let's say that John chooses the sequence--12, 14, 16--to test whether or not the general rule he has formulated is correct. Given what he already knows about the first two sequences (2, 4, 6, and 18, 20, 22), it is very likely that he will be told that this new sequence also fits the actual general rule. In other words, choosing the sequence--12, 14, 16--will give him no new information. In fact, most people, because of the confirmation bias, will choose this sequence even though it cannot help them to determine if the rule that they have generated is correct or not.

What John needs to do is to try to disconfirm the rule that he has generated. Thus, he should choose the other sequence of numbers: 7, 9, 11. This will give him information, no matter what response he gets. If he is told that this sequence does not fit the general rule, then the rule that he formulated is supported (that is, he should become even more certain that he has figured out the actual rule used to generate the first two sequences). On the other hand, if he is told that the sequence--7, 9, 11--also fits the general rule used to generate the first two sequences, then this tells him that the rule that he formulated--any ascending series of three consecutive even numbers--must be wrong. Other possible general rules for John to look at are:

• any ascending series of three numbers that increase by two (such as 13, 15, 17, and 20, 22, 24)
• any ascending series of three numbers that increase by any amount (such as 1, 5, 22, or 25, 26, 35)

Thus, when faced with a question to answer, we first need to consider several alternative answers. This will help us to avoid the confirmation bias. If we immediately consider only one possible answer, it becomes more likely that we will unthinkingly look only for evidence that confirms this answer. But, by realizing that there is more than one possible answer, we become better able to look for any evidence that may disconfirm an answer that we are considering.