Hmmm, Should I Switch That Answer?
Test takers and givers have long debated whether it is wise to stick with your initial answer or switch when in doubt. The usual suggestion is to stick with your “gut reaction”, but does the data bear this out? Actually, no. This article at PSYBlog discusses the data, and conjectures about the reason. I’m sure there are variables they didn’t measure (e.g. how unsure do you need to be to consider switching?), but the result is intriguing. Here is their take:
The standard advice for multiple-choice tests is: if in doubt, stick with your first answer.
College students believe it: about 75% agree that changing your first choice will lower your score overall (Kruger et al., 2005). Instructors believe it as well: in one study 55% believed it would lower students’ scores while only 16% believed it would improve them.
And yet this is wrong.
One survey of 33 different studies conducted over 70 years found that, on average, people who change their answers do better than those who don’t (Benjamin et al., 1984). In none of these studies did people get a lower score because they changed their minds.
Study after study shows that when you change your answer in a multiple-choice test, you are more likely to be changing it from wrong to right than right to wrong. So actually sticking with your first answer is, on average, the wrong strategy.
And why does the convention disagree?
Why do so many people (including many who should know better, like the authors of test-preparation guides) still say that you should stick with your first answer?Kruger et al. (2005) argue that it’s partly because it feels more painful to get an answer wrong because you changed it than wrong because you didn’t change it.
So we tend to remember much more clearly the times when we changed from right to wrong. And so when taking a test we anticipate the regret we will feel and convince ourselves that our first instinct is probably right (when it’s probably not).
(HT: DeAnna McDonald)
No Longer Normal 
There was a mythbuster’s episode that went through the Monty Hall paradox from the “Let’s Make A Deal” game show which discussed the statistical analysis of whether or not you increase your odds of winning by changing your initial guess. While this article mentions the emotional rationale for why we don’t change our answers, I think the Mythbusters showed the stastical rational TOO change.
I could be wrong, but why second guess? 😉
Key differences with the Monty Hall problem are that there are three choices, you are guessing, and one wrong choice is revealed. With this, you are making an educated (hopefully) guess. The reason switching actually works out better (IMO) may be that you have a reason for thinking that a new answer may be better. That reason is likely related to memories/knowledge of the setting of the question, so it indicates that your first answer might be wrong. You shouldn’t switch answers you KNOW are right (which they never happen to mention). I do wonder how your confidence in your answer plays in. Should you switch if you are 70% sure of the initial and 30% sure of the second guess? 60/40? Where does it start to make sense to stay with the your initial, and when does it become smart to switch. This should be studied (by someone other than me) more closely!