# Use Statistics To Make Better Guesses On Exams

3

When your teachers are writing multiple choice or True/False tests, they’re supposed to keep things as random as possible. However, as the BBC points out, there is a pattern in that randomness, and knowing what it is might help you get through your exams.

Photo by Ryan M

Writer William Poundstone crunched the numbers on a bunch of different tests and exams and found that even in the randomness, you can use those statistics to improve your chance of getting an answer right. For example, True/False tests might seem random, but as long as you know a few answers, you can improve the chances your chances of an educated guess. Here’s what Poundstone suggests you do:

— Go through the entire test, marking the answers you know, before attempting to make any guesses.

— Look at the known correct answers of the items before and after the one(s) that’s left you stumped. When both neighbouring answers are the same (both false, let’s say), guess the opposite (true).

— Should the before and after answers be different, guess true (because true answers are more likely overall).

With multiple choice questions, things get a bit harder to quantify, but Poundstone breaks down the numbers like so:

So to recap, pick the second answer (B) on four-choice tests and the fifth answer (E) on five-choice tests.

It’s not all statistics though. Poundstone found a few other commonalities that can help you make better guesses. If “none of the above” or “all of the above” are options, they’re more likely to be the right answer than the others. Likewise, the longest answer tends to be the right one as well. Finally, Poundstone suggests you look for “continuity errors”. This is when an exam setter uses an article like “an” instead of “a” at the end of the question. Chances are, when they do that, they’re revealing the answer to you unknowingly. Obviously these guesses aren’t a replacement for actual studying, but they might help you in a pinch. Head over to the BBC for a bunch more tips.

The secret to acing exams [BBC Future]

• tazza says:

I once sat an exam where all but one of the true/false answers (about 20, I think) were true. The guy who wrote that exam knew exactly how to mess with people.

• barb says:

I had one where ALL FIFTY were FALSE. Evilness personified in an Old Testament Bible-as-literature prof, who knew just how to give us the experience of being at the mercy of the OT God.

• Clive says:

Ah…the OT God who relented from punishment when asked, who wanted adult children to look after their parents (essential in a nomadic group), and to protect his people from the child sacrificers and paederists that lived around them…think ISIS when you think of the tribes that opposed Israel.

• kapone says:

I once did a test answering a, b, c, a, b, c … for a language class in high school (I paid zero attention the whole year). Ended up getting 100% and a report from the teacher that it was disappointing I hadn’t submitted any work all year as I ‘clearly’ knew the material.