What you don’t know can help you, if you play the percentages
By Bradley Everett, Special to UnionvilleTimes.com
If you search for “Should I Guess on the SAT” on Google, you will get about 196 Million results (and a lot of different answers). So we’ll take a stab at giving you an answer with the 196 Million and first.
You get one full point for each correct answer and lose 1/4 of a point for each incorrect answer. However, you neither gain nor lose anything with an answer left blank. With that in mind, it would take 4 wrong answers to offset one correct answer. Let’s look at it on a probability basis.
Each multiple choice question gives you 5 choices. Let’s say there are 30 questions throughout the test that you aren’t sure of. However, you may know enough about a question to eliminate some answers as not being the correct answer (for example, you don’t know if the answer is ‘canal,’ ‘thoroughfare’, or “street,” but you know it’s not ‘digital.’ You could cross out ‘digital’ and guess out of the remaining 4 choices. Let’s see how your score would change based on how many “wrong” answers you are able to eliminate.
No Idea At All. Let’s say you are completely clueless, and can not eliminate any answers. Guessing randomly out of 5 questions, you can expect to get approximately 6 correct and 24 wrong. You would get 6 points for the right answers and lose 6 points (24 x .25) for the incorrect answers. The net raw score from guess is 0. So, as you can see, guessing with no eliminated answers will likely not help (or hurt) very much. It may just be a waste of time.
Eliminate One Choice. If you can eliminate JUST one choice, the odds begin to swing in your favor. If you can eliminate an answer, you are really guessing out of 4 choices, so you can expect to get approximately 7.5 questions right and 22.5 questions wrong. This translates into a raw score of 1.875. Scores aren’t calculated this way (with decimals), but we want to provide an average of how your score can improve.
Eliminate Two Choices: By eliminating two choices, you can guess out of three, rather than 5, answer choices. Over 30 questions, you can expect to get around 10 of them right, and 20 of them wrong. This translates to a raw score of 5.
Eliminate Three Answer Choices: If you can get rid of 3 answer choices and just guess out of 2 choices, you are in really good shape. You can expect around 15 correct answers out of 30 and 15 incorrect. This equates to a raw score of 11.25.
As you can see, with each answer choice you are able to eliminate, you greatly improve your chance of increasing your raw score over the course of the test. As a rule of thumb, if you can eliminate one answer choice, GUESS! Remember, eliminate answers very discerningly! If you eliminate the Correct answer, you’ve already guaranteed you will not get that question right.
For grid-in questions (on the math section), ignore everything I just said. No points are taken off for wrong answers, so guess on all of them!
Bradley Everett founded Unionville-based The Thinking Cap in 2007 to help local students achieve their academic goals. He received a degree in Applied Mathematics from The Johns Hopkins University in Baltimore, Maryland. He has spent the majority of his career in the investment industry, beginning on the advisory and retail side before turning to analyst and research roles. He has completed all three testing levels of the Chartered Financial Analyst program. His unique background has helped to provide equally unique methods to help students in all levels of mathematics.