It depends on the answer key.

Guessing 'C' all the way down and expecting 25% assumes that the distribution of answers is roughly equivalent across the whole test. This is an extra variable you can't account for without knowing the answers.

Whereas, if you pick a random answer for each question, you will answer 25% correctly, assuming an infinite number of questions. However this strategy has error bars that grow as the number of questions gets smaller.(ie: you are far more likely to end up with more or fewer than 25% correct in practice)

The best strategy for any given multiple choice question that you don't know the answer, is to eliminate options that are definitely incorrect, leading to a much higher chance of success with a random guess.

Or just study the content more, as breadsmasher suggested.

Back when I was in school, we had an honors class focused on test taking. One of the exercises we did was taking multiple choice tests where we were unlikely to know or understand the content being tested.

The idea was to read through the test and quickly scan for information that could be used to answer other questions on the test.

After doing that and filling in the answers that were provided by the material itself, you looked for predictable patterns in the answers; this differed depending on the test. For an answer key created by hand where the test writer doesn’t know about “pick c” C is the best answer. But these days, test writing software usually “randomizes” the answer order, attempting to make each answer a truly random letter.

But “random” is rarely truly random, and the human eye can often spot distributions and patterns once enough answers have been filled in.

And this brings us to the key bit: usually with multiple choice there will be one answer that’s obviously wrong, one correct answer, one answer that illustrates you understand the technique but not the general concept, and one that reflects a common error.

If you can identify which answer is likely to be each of those, they’ll also have a distribution and a pattern, and these can help you eliminate incorrect answers and highlight the correct solution.

Using these analytic techniques, it’s usually possible to score at least 80%, although the success rate generally improves with the length of the test and the amount of time provided to do the analysis.

We had it drilled into us that, after we’d filled out the answers based on our knowledge and skill, to ALWAYS leave time to go back and run these techniques against the test to ensure that we hadn’t made mistakes AND to gain a deeper understanding of the particular test writer to apply against their future tests.

I find it’s best to know the answers beforehand.

or you could study

its really about eliminating definately wrong answers. if you eliminate one now the guess is 33%. eliminate 2 and its a straight up 50/50 and of course if you eliminate 3 then you have the answer.

As someone building quizzes as part of my job, my strategy is usually to assign the correct answer to C or D by default, but then i would randomly change to the others options in an attempt to homogenize the answers. I definitely like using A more than B (not sure why)

Having said all that.... be careful if you're taking a quiz on Canvas or Blackboard, both offer the option to randomize the multiple choice answer list so the order is different for each person.

We had negative marking for incorrect answers to account for the assumption that you start w From a baseline of 25%. So, optimal strategy was to not answer questions if you didn't know the answer with a reasonable level of confidence.

If there’s all of the above, choose that.

When I was in a class specifically for competing in Academic Decathlons, we were told if we didn't know the answer to just pick C because not answering deducted more points than being wrong, and statistically, C was going to be the correct answer more often than not on a 4 choice question.

The one pattern that shows up frequently is that repeat answers are less likely than statistics would suggest. For example, if the answer to question #2 is C, then the answer to question #3 is much less likely to be C.

This is because people designing tests want the answer patterns to look more 'random', so they overcompensate trying to avoid streaks of the same answer over and over again. But in a truly random set, streaks would happen from time to time.

Less of an issue in software-generated tests, though, because the software often handles the randomization and doesn't have such biases. But for hand-made tests, it's a fairly reliable trend.