How to write good multiple choice questions

Start with one idea

Every MCQ should test one idea. Before you write, finish this sentence: "After this lesson, the student should be able to ___." Then write a question that checks exactly that.

If a question needs two facts to answer, a student can get it wrong for either reason and you will not know which. One idea per question keeps your marks meaningful.

Spread your MCQs over the chapters you taught. Do not let one favourite chapter fill the whole objective section.

Write a clear stem

The stem is the question part, above the options. A good stem can be understood before the student reads any option.

• Put the main words in the stem. If every option starts with the same words, move those words up into the stem.
• Ask a full question or write a sentence that is easy to finish. Avoid a stem that is only a single word.
• Keep it short. Remove any story that does not help the student think.
• Say it in the positive. "Which of these is a noble gas?" is clearer than "Which of these is not a metal?"

If you must use a negative word such as "not" or "except", write it in capital letters or bold, so a tired student does not miss it.

Make exactly one answer correct

The key must be defended by your textbook or your teaching. Read each option as if you were a clever student looking for a second right answer. If you can argue for two, change one of them.

Watch for questions whose answer depends on opinion, on the year, or on a rule that different books state differently. Those are risky in a test.

After you finish the paper, write the answer key at once while the question is fresh in your mind. A key written weeks later is where mistakes appear.

Build distractors that look possible

Distractors are the wrong options. Their job is to attract the student who has not learned the idea. A silly distractor wastes space, because nobody picks it.

Good sources of distractors are real mistakes students make:

• a nearby fact that is true but answers a different question;
• the result of a common calculation error, such as adding instead of multiplying;
• a word that sounds like the right one;
• a rule applied in the wrong situation.

Keep the options similar in length, style and grammar. If the correct option is always the longest one, students will learn to pick it without reading the question.

Traps to avoid

• "All of the above" and "None of the above". A student who knows two options are correct can guess "all of the above" without checking the third. These options also test guessing more than knowledge. Use them rarely, or not at all.
• Grammar clues. If the stem ends with "an" and only one option starts with a vowel, you have given the answer away.
• Absolute words. Words like "always" and "never" are often wrong, and students know it.
• Repeating a pattern. If the answer is "C" five times in a row, students notice. Mix the positions of the correct option across the paper.
• Trick questions. A test should find out what students know, not whether they can be fooled.
• Copying a sentence from the book and removing a word. That tests memory of the page, not understanding.

Use the right number of options

Four options is the usual choice, and it is a good one. Three options can be enough if you cannot find a believable fourth. A weak fourth option adds nothing, because students dismiss it at once. It is better to have three strong options than four where one is silly.

Keep the options in a natural order where one exists. Put numbers from smallest to largest, and dates from earliest to latest. This stops the order from giving hints and makes the question easier to read.

Avoid options that overlap, such as "more than 5" and "more than 10". A student who picks the second has also picked a true statement in the first, and you will have two correct answers without meaning to.

Check the questions before you print

Read the whole objective section once more as a student would, with a pencil, and answer every question without looking at your key. If you hesitate on any question, so will some students. Fix it or remove it.

Ask a colleague to attempt a few. A second reader will find an unclear stem or a second correct answer in a minute.

In Paper Desk, an MCQ has a question box and four option boxes, so you only type or paste the text; the layout is already built. You can switch on an answer key page and an OMR bubble answer sheet for your MCQs when you want quick marking. See how to use Paper Desk, or open the paper maker and try it.

To plan how many MCQs to include and how many marks they carry, read how to balance a paper.