The College Board announced Wednesday that it plans to overhaul the format of the popular college admission test, the SAT. The vocabulary section will shift its focus to words used in modern life, the essay portion will become optional, and the possible top score will return to a measly 1,600 — down from the current 2,400.
One particularly striking change, at least from a numbers perspective, is in the scoring of the SAT’s multiple-choice questions. In the past, a correct answer would add a point to the test-taker’s raw score, but an incorrect answer would dock a quarter of a point. Skipping a question had no effect. (This scoring system was meant to discourage test-takers from simply guessing at the answers.) Starting in 2016, the SAT will no longer impose the quarter-point penalty for a wrong answer.
Eliminating the writing portion and the need to understand relationships between sets of esoteric words each make sense for an exam whose creators are striving to maintain relevance and to improve accessibility across income levels. But why drop the penalty for guessing?
Carly Lindauer, a spokeswoman for the College Board, said there were two reasons. First, research demonstrated the change wouldn’t have an impact on scores reported.1 Second, Lindaur said that moving to the new scoring system “eliminates any test-taking strategies that students may be using that are irrelevant to what we are measuring in the test.” The SAT is getting out of the business of testing students’ understanding of probability, it would seem.
Yet by encouraging guessing, the College Board is introducing statistical noise to the scores. Maybe my score is 1,200 ± 30 under the current system, and it’s 1,200 ± 40 under the new system. A possible 10-point gain, achieved by guessing, doesn’t mean I know the material on the exam any better — it just means I’m luckier.
And that means a big change in how students approach the exam.
The quarter-point deduction for an incorrect answer was originally devised to reduce the amount of guessing on the SAT and as an incentive for students to leave blank those questions they didn’t understand. Since any given multiple-choice question had five possible answers, randomly guessing gave you a one-in-five chance of getting it right. If you guessed on five questions in a row, on average you would get four wrong and one right. One point gained and four quarter-points lost gives you a net gain of zero.
If you guessed on the entire critical reading exam, you’d most likely get between 12 and 14 questions right.
In the current system, with the quarter-point penalty, guessing on every question would (combining this analysis with published College Board statistics) give you a score of between 200 and 240 out of 800 on this segment of the exam. Since 200 is the absolute minimum score, you’d perform about as well as if you got every single question wrong.
Clearly, guessing the entire SAT is not an exceptional strategy for acing the exam.
But let’s say you guessed just 25 of the 67 total critical reading multiple choice questions. You’d most likely get five of those guesses right. With the quarter-point penalty for the 20 you’d get wrong, you’d gain zero points overall. Eliminate the penalty, and your expected raw score for these 25 questions is 5.
What’s needed, then, is a fundamental change in tactics for SAT-takers. Since the exam’s inception, students were advised to only guess on a question if they could eliminate at least one of the answers. This put expected value on their side, and they could hope to come out ahead in the long run.
Starting in 2016, with the death of the quarter-point penalty on wrong answers, there’s absolutely no reason anyone should ever leave a question blank on the SAT. According to College Board statistics, in 2012, every five points added to a test-taker’s raw score meant an additional 30 to 80 points on her curved final score.
So guessing isn’t just advisable, it’s about to become strategically crucial for people seeking to maximize their performance. Granted, everybody guessing is probably going to increase the average raw score, but that just means the College Board will adjust its grading curve commensurately.
If you choose not to guess, you risk falling behind the pack.