AO3Synthesis & Evaluation
IB Command Term: Explain
What does "Explain" mean in IB exams? Learn the difference between Explain and Describe, how to structure your answer, and tips from IB examiners.
IB Definition
"Give a detailed account, including reasons or causes."
Marks: 3–6 marksAssessment Objective: Objective 3
What You Need to Do
Say WHAT happens AND WHY. Use linking words like "because", "therefore", "this leads to".
How to Structure Your Answer
- 1State the WHAT — identify the factor, concept, or process
- 2Give the WHY — provide a reason or cause using causal language
- 3Develop with an example or data if marks allow
- 4Link back to the question context
Example Exam Questions
- “Explain two factors that affect the rate of photosynthesis.”
- “Explain why biodiversity is important for ecosystem resilience.”
- “Explain the concept of economies of scale with reference to a named business.”
- “Explain the law of diminishing marginal returns.”
Common Mistakes
- ✗Only describing (WHAT) without giving reasons (WHY)
- ✗Not using causal language (because, therefore, as a result)
- ✗Giving only one reason when the question asks for multiple
- ✗Writing too much for low-mark questions
Examiner Tip
Must include reasons or causes — "describe" says WHAT, "explain" says WHY.
Where This Term Appears
ESSHighBusiness ManagementHighEconomicsHigh