why multiple-choice questions suck

A psychological quirk among people who don't use much care in drafting multiple-choice questions is that they will almost always make the correct answer the longest (or the shortest) answer. Here's a recent multiple-choice quiz from Dictionary.com. Notice anything?

QUESTION 1
What does GIRASOL mean?*
a. a sunflower, having edible, tuberous, underground stems or rootstocks
b. a trinket; a bauble
c. a large marble

QUESTION 2
What does ALLEY-OOP mean?
a. a whispering or rustling sound
b. used as a shout of encouragement, exhortation, or the like
c. light, playful banter

QUESTION 3
What does ÉCOSSAISE mean?
a. a country-dance in quick duple meter
b. love of or taste for fine objects of art; also, productions of art
c. a descendant; an heir

QUESTION 4 
What does HADAL mean?
a. of or belonging to the summer
b. of or relating to the greatest ocean depths
c. situated beneath the moon; terrestrial

QUESTION 5
What does TERRICOLOUS mean?
a. having great diversity or variety
b. high-spirited
c. living on or in the ground

QUESTION 6
What does COQUETTISH mean?
a. drying or scorching with heat; burning; parching
b. dull; sluggish; apathetic
c. characteristically flirtatious, especially in a teasing, lighthearted manner

QUESTION 7

What does HOBSON-JOBSON mean?
a. mutual courtesy; civility

b. the alteration of a word or phrase borrowed from another language
c. idle, trifling talk

If you selected the longest answer in each case, you'd get 5 out of 7 questions right without even knowing any of the vocabulary words. Only Questions 3 and 5 don't follow the pattern I mentioned. This is one reason why multiple choice is such a horrible method for testing knowledge. I discuss this very issue in my book, along with the idea that, in theory, you can guess your way through any multiple-choice test. Even the best-written multiple-choice questions offer a chance for correct guessing. You're better off with short answers, fill-in-the-blanks, essays, or (in some cases) draw-your-answer.

If you insist on creating multiple-choice questions, throw the kids off by saying "select all that apply" or warning that "there may be more than one correct answer." Make it so that some of your questions contain nothing but correct answers. This is a psychological trick, too, because most kids will refuse to believe that "all correct" is a possibility: at least one of the answers has to be wrong! Also, use better distractors. For example, Question 5 above asks what terricolous means. Anyone with half a brain can easily make the connection between the terr- root and any notion of "ground" or "earth," so as the question is written, the answer should be obvious. (You've now scored at least a 6 out of 7.) It's also obvious, though, because the other answers have nothing to do with ground or earth. This is where it's a good idea to put in some distractors. Rewritten:

QUESTION 5
What does TERRICOLOUS mean?
a. shaped like a turtle
b. made of multicolored earth
c. living on or in the ground

Notice how (1) the correct answer is neither the longest nor the shortest answer (that was true before, but it's still true), and (2) I've placed better distractors in for (a) and (b). The (a) distractor might trigger someone to think of terrapins, a type of turtle, and the (b) distractor might tempt someone to think the etymology of terricolous has to do with earth and colors (-colous = "inhabiting"**). You can still guess the correct answer to the question, but it's undeniably a better-written question than the original. Someone will object that, if you're always avoiding making your correct answer the longest or the shortest selection, students will catch on to that fact. I agree. So throw in a few answers that break the pattern.

Multiple-choice questions require some thought and care in their creation, but all in all, multiple choice is a horrible, horrible way to test knowledge. Teachers rely on the format, though, because they're lazy, and such questions are easy to score. If you're a teacher, and you have to write multiple-choice questions because your department says you must, then use the suggestions I've given above to make your quizzes a bit more rigorous. Otherwise, if you have the freedom to use other knowledge-checking methods, go with those, I beg you.

__________

*I found girasol amusing because, in French, a sunflower is a tournesol, a "turn to the sun." You can see the relationship between gyrating (gira-, Italian root) and turning.

**Arenicolous = living in sand.