ExamEval
Item Writing Flaws
Negative Phrasing

Negative Phrasing in Exam Questions: Why "Not" and "Except" are Not Unlikely to Not Fail at Not Confusing Students

By Sean P. Kane, PharmD, BCPS

Published June 21, 2025

Why Negative Phrasing is a Problem

Negatively worded questions (using words like "not" or "except") are common in exams, but research and best practices recommend using them only when absolutely necessary. In general, a negatively stemmed question increases the question's difficulty without improving its discrimination. Negative stems tend to cause students to miss the question because it was confusing or they cognitively misinterpreted the negative stem, leading to an incorrect answer not due to a knowledge deficit but due to misunderstanding the wording of the question.

Negative stems ask students to find the least accurate or least appropriate option, rather than the most accurate one. This is a different mental process and can easily cause test-takers to make mistakes, especially if most other exam questions are phrased positively. If a negative word is used, it should be highlighted in some way (bolded, capitalized, or underlined). However, even with this formatting, a negatively stemmed question tends to perform worse than a positively stemmed question.

Critical Issue

Negative phrasing increases cognitive load and introduces construct-irrelevant variance. The question becomes a test of reading comprehension and attention to detail, rather than a pure measure of content knowledge. This can lead to lower scores for students who understand the material but are confused by the wording.

Double Negatives and Cognitive Load

The cognitive load imposed by negative phrasing is magnified when double negatives are used. A question like, "Which of the following is not an uncommon side effect?" is unnecessarily confusing and forces students to perform mental gymnastics to understand what is being asked. This complexity does not add to the assessment of content knowledge; it only serves to obscure the question's intent.

As Dell and Wantuch (2017) recommend, questions should be phrased positively whenever possible. If a negative stem must be used, it should be clear, concise, and avoid double negatives. The goal is to assess knowledge, not to trick students with confusing language.

Example of Negative Phrasing in Health Sciences Education

In the following example, the intent of the question is to assess students' understanding of the initial management of sepsis. Because the negative stem word ("NOT") is in the middle of the question, test-takers may inadvertently ignore the "NOT" and answer the question positively, resulting in an incorrect answer.

Flawed Question

Which of the following is NOT an appropriate initial management step in a patient with suspected sepsis?

A. Obtain blood cultures before starting antibiotics

B. Start vasopressors before administering IV fluids ✓

C. Administer IV fluids using balanced crystalloids

D. Identify the source of infection

The negative phrasing "NOT an appropriate initial management step" requires students to identify correct actions and then select the one that is incorrect, increasing cognitive load and the chance of error due to misunderstanding the question structure.

Corrected Question

Which of the following is an appropriate initial management step in a patient with suspected sepsis?

A. Obtain blood cultures before starting antibiotics ✓

B. Start vasopressors before administering IV fluids

C. Place an arterial line for continuous blood pressure monitoring

D. Administer 5% albumin 30 mL/kg if lactate levels are ≥ 2 mmol/L

The corrected question uses positive phrasing, allowing students to focus on identifying correct management steps for sepsis without the confusion of a negative stem.

When is Negative Phrasing Acceptable?

Sometimes, it is important to know what not to do (for example, contraindications or safety warnings). In these cases, a negative question may be justified; however, this format should be used rarely due to worse student performance compared to positively phrased questions. If negative phrasing must be used:

Highlight the negative word (bolded, capitalized, or underlined).
Place the negative word at the end of the question if possible.
Keep the question as simple as possible.

In the following example, a negative stem is used but follows best practices to reduce the risk of student confusion and inadvertently answering incorrectly:

Flawed Question

Direct oral anticoagulants (DOACs) offer several advantages over warfarin, EXCEPT in which of the following situations?

A. When rapid reversal of anticoagulation is required

B. In patients with mechanical heart valves ✓

C. For stroke prevention in nonvalvular atrial fibrillation

D. For treatment of deep vein thrombosis

The negative phrasing ("EXCEPT") requires students to identify all correct advantages and then select the exception, increasing cognitive load and the risk of error due to misunderstanding the question structure.

Corrected Question

Direct oral anticoagulants (DOACs) are preferred over warfarin in most situations EXCEPT:

A. In patients with mechanical heart valves ✓

B. For stroke prevention in nonvalvular atrial fibrillation

C. For treatment of deep vein thrombosis

D. For extended prophylaxis after orthopedic surgery

The corrected question retains a negative stem but follows best practices: the negative word is bolded and placed at the end of the question, and the question is kept as simple as possible.

Best Practices for Negatively Stemmed Questions

Use positive or affirmative stems whenever possible (e.g., "Which of the following is correct?" instead of "Which is NOT correct?")
Never use double negatives.
Focus on what students should do, not what they should avoid.
Use scenarios to test knowledge of exceptions or contraindications in a positive way.

Poorly constructed negative stems can undermine the validity of exam results and hinder accurate assessment of student knowledge. This persistent challenge in exam design can lead to unreliable outcomes and missed opportunities for learning improvement. ExamEval, an AI-powered exam analysis platform for health professions educators, addresses these issues by automatically detecting item-writing flaws, enhancing assessment reliability, and supporting better student learning outcomes.

References

National Board of Medical Examiners (NBME). Item-Writing Guide. Philadelphia, PA: National Board of Medical Examiners; February 2021.
Haladyna TM, Downing SM, Rodriguez MC. A review of multiple-choice item-writing guidelines for classroom assessment. Appl Meas Educ. 2002;15(3):309-334. doi:10.1207/S15324818AME1503_5
Tarrant M, Knierim A, Hayes SK, Ware J. The frequency of item writing flaws in multiple-choice questions used in high stakes nursing assessments. Nurse Educ Today. 2006;26(8):662-671. doi:10.1016/j.nedt.2006.07.006
Dell KA, Wantuch GA. How-to-guide for writing multiple choice questions for the pharmacy instructor. Curr Pharm Teach Learn. 2017;9(1):137-144. doi:10.1016/j.cptl.2016.08.036