MCQ Writing
How to write flaw-free multiple-choice questions — common item-writing flaws, distractor counts, stem wording, and evidence-based MCQ rules.
Multiple-choice questions carry most of the assessment load in medical education, yet the evidence shows that a large share of locally written items are flawed. Tarrant, Knierim, Hayes and Ware (2006) found that roughly 46% of items on nursing examinations contained at least one item-writing flaw, and similar problems appear wherever faculty write questions without formal training. Flawed items matter because they change what a test measures: cues such as the longest option or grammatical mismatches let testwise students guess correctly, while negatively worded or convoluted stems penalize students who know the content. Both effects add noise to scores and can shift pass-fail decisions for borderline examinees, a point Downing (2005) documented in medical school examinations.
The good news is that item-writing quality is teachable. A small set of evidence-based rules — synthesized by Haladyna, Downing and Rodriguez (2002) and codified in Case and Swanson's NBME item-writing guide — eliminates most common flaws. This topic covers those rules: the flaws to look for, how many options an item really needs, why negative stems cause trouble, and simple quality checks like the cover-the-options test.
Questions & answers
How many distractors should a multiple-choice question have?
Most multiple-choice questions need only two or three distractors. Rodriguez (2005), synthesizing 80 years of research, found three-option items (two distractors) perform about as well as four- or five-option items, because writers rarely produce more than two plausible distractors. Prioritize distractor quality over quantity.
Read the full answer →Is "all of the above" a bad answer option?
Yes — "all of the above" is widely discouraged. Examinees who recognize two correct options can pick it without knowing the rest, and recognizing one wrong option eliminates it. Haladyna, Downing and Rodriguez (2002) advise avoiding it; testing multiple true facts is better done with separate items.
Read the full answer →What are the most common MCQ item-writing flaws?
The most common MCQ flaws include implausible distractors, negatively worded stems, "all of the above" and "none of the above" options, longest-answer cues, grammatical cues between stem and options, and unfocused stems. Tarrant et al. (2006) found roughly 46% of nursing exam items contained at least one such flaw.
Read the full answer →What is the cover-the-options rule in MCQ writing?
The cover-the-options rule is a quality check from Case and Swanson's NBME item-writing guide: cover the answer choices and read only the stem. If a knowledgeable examinee can supply the answer from the stem alone, the item is focused; if not, the stem needs rewriting.
Read the full answer →Why should negatively worded stems be avoided in MCQs?
Negatively worded stems ("Which is NOT…", "All EXCEPT…") add reading burden without testing more knowledge, are easily misread by hurried or non-native examinees, and reward test-taking care over content mastery. Haladyna, Downing and Rodriguez (2002) recommend wording stems positively; if a negative is unavoidable, emphasize it with capitals or bold.
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