There’s a ton of conflicting advice about this on the web, and many teachers/guidance counselors/test prep tutors get this wrong.
I’m not the only one who will give you sound advice here. Experts whom I recently recommended, such as PencilNerd and PWN The SAT, got it right also. The math isn’t that hard to understand. I intend to add some information about students’ psychology to the discussion.
When you take the SAT, you are initially given a raw score based on how many questions you get right, wrong, or blank. That raw score is then converted into the scaled score you see on your report, but we don’t have to worry about the scaled score here.
On all multiple choice questions, your raw score is equal to the number of questions you get right minus one quarter of the ones you miss (R – 0.25W). Blanks count as zero. (on the student-produced answers on the math section, nothing is subtracted for wrong answers).
If you close your eyes and guess randomly, on the average you’ll guess 1 out of 5 right. For those 5, you score 1 – 0.25(4) = 0. That’s exactly the same as you’d have gotten by leaving them all blank. No penalty for guessing!
Of course, students can guess worse than random by choosing trap answers. But since you know all about traps (if you don’t, just read my recent post about them), you should know to avoid them and guess better than random even if you have no idea what you’re doing. Eliminate even one answer, and the odds shift way in your favor.
But the truth is, I have been telling my students to guess for over 25 years, and many of them still don’t follow my advice (at least not without a lot of pushing). Why is that? The math is simple, and the logic unassailable. When those students finally do guess, their scores go up (a little bit – no one ever aced the SAT by guessing alone). So why don’t these students want to help themselves?
The answer is psychology. Some are afraid to guess. Others lack self-confidence. And a few students actually think guessing is unfair. If you’re already convinced you should guess, fine. Otherwise, read on. You may learn something about yourself.
Fear of Risk-Taking
This is very common. Some of us like to take risks; others simply don’t. Studies indicate that a higher percentage of men than women are risk-takers, but there are plenty of exceptions of either gender. Do you like to play poker? If yes, you probably don’t mind guessing either.
Suppose you’re fairly sure you can eliminate one answer. Chances are, some of the other answers look better than others; the trap concept tells you which ones to guess. Even if you can only guess 1 out of 4, you’ll add 1 – 0.25(3) = 0.25 to your raw score for every four questions. If you have a 1-in-4 chance to win $100, and you stand to lose $25 the rest of the time, you should certainly take the bet. But many folks won’t. “I’m not a gambler,” they protest. “The game must be rigged.”
But the truth is that most successful people are risk-takers. The key to succeeding is knowing which risks are worth taking. But you can’t win if you won’t take any risks.
“If I guess, I’ll probably get it wrong, so I’m better off just leaving it blank.” No, no, no! The reward is 4 times as large as the penalty! It’s worth a shot at glory.
Suppose you’re not a basketball player, and someone offers you an iPod if you can hit a foul shot in front of some friends. Win – iPod, lose – look a bit foolish. Shoot!
Lack of Self-Confidence and Pessimism
This is not quite the same thing as fear of risks. Some people believe that the laws of probability don’t apply to them. They think that some higher force has stacked the odds against them; most people win a coin flip half the time, but they do worse because they’re “cursed.” The easiest way to convince yourself (or someone you know) that this isn’t so is to try it empirically. Flip that coin 30 times or so (a small wager can add substance to the lesson – bet on cookies if you don’t want to gamble for money).
Guessing is Unfair!
It may strike some of you that this kind of thinking is very strange. But I’ve found that the “moral anti-guessers” are quite vehement in their beliefs; it can be very hard to change their minds. The idea is that society rewards you for hard work (in this case, learning how to solve SAT questions), and guessing is a form of “cheating the system,” since you’re getting points for problems you don’t know how to solve. That’s nonsense. The reason you lose only a quarter-point for a wrong answer is that The College Board wants to give you partial credit. If you can eliminate 3 answers instead of just 1 or 2, you will tend to score higher by guessing. So students who eliminate more answers are rewarded with higher scores – what could be more fair? If you don’t guess, you chuck away that advantage – that’s unfair.
Finally, is there ever a reason not to guess on the SAT? Let’s just say that such circumstances are so rare that you can effectively ignore them. If you’re 5 seconds away from finishing the next-to-last math problem, yet suddenly decide to guess the last two instead, that might be a poor choice. Of course, if you rarely solve the last few questions anyhow, it might be a good one. Just…
“Guess Your Face Off!”