It’s a tip I hear often and I don’t quite understand.
If the time is nearly up and you have to fill in answers for multiple choice, A,B,C,D for example. Why would you only go with ‘A’?
You should get around 25% of the answers correct but no proper test is ever going to have ‘A’ as correct answer many times in a row.
Would it not be marginally better to just pick at random?
Why not?
Edit: I understand real world is rarely truly random, but is my thinking here correct given answers are randomly distributed?
In: 0
As others have stated, *if* the exam has its answers distributed truly randomly (or at least sufficiently randomly, i.e. by a computer), and *if* all of the answers had their choice selection decided independently, then your guesses will not matter at all. You gain no statistical advantage by any strategy. You are simply rolling an X-sided die Y number of times, where X is how many choices each question has and Y is how many questions the exam has.
The adage that you should select the same letter multiple times in a row to get an edge stems from two things, one of which is completely unrelated (and may not apply) and the other only holds if the assumptions we made aren’t true.
The first is about speed. If you mark every question with *something*, you are statistically expected to get *at least* a score of 1/X on all those questions you marked. So if you anticipate the possibility that you might not even finish your exam, if you have them all pre-marked (switching answers to the correct ones as you read your way through the exam for real), then you might get some extra scoring for your guesses on questions you may have otherwise marked blank. This only works, of course, if the exam you are taking doesn’t penalize incorrect answers. An exam that marks non-answers and wrong answers the same benefits from guesses; an exam that subtracts points for wrong answers and does nothing for non-answers punishes guesses.
The second is that there is some evidence that in multiple-choice exams with answer keys arranged by humans one letter is statistically more likely to be the answer for any given question. In the common four-choice arrangement with A, B, C, and D, that letter tends to be C. So, provided your exam was written by a human, *and* the exam doesn’t penalize guessing, answering all questions with C has a statistical advantage over random guessing.
Latest Answers