IB Command Terms Explained (With Real Examples)

IB Command Terms Explained: With Real Examples

IB examinations do not only test what students know. They also test whether students understand what a question is asking them to do.

This is where IB command terms become important.

Words such as define, describe, explain, analyse, compare, discuss, evaluate, and justify tell students how they should structure their answers. Understanding these terms can help students avoid giving too little or the wrong type of information.

A student may know the correct concept but still lose marks by answering a question at the wrong level.

What Are IB Command Terms?

Command terms are words used in IB assessment questions to indicate the type and depth of response expected.

For example:

"Define" usually requires a concise meaning.

"Explain" requires more than a definition. You need to show how or why something happens.

"Evaluate" requires judgement supported by evidence.

The exact expectations can vary by subject, so students should always consider the context and the relevant subject-specific assessment guidance.

1. 1Define

What It Means

Give the precise meaning of a term or concept.

Example

Question: Define opportunity cost.

What the Answer Should Do

Give a clear and accurate definition without unnecessary explanation.

Example answer: Opportunity cost is the value of the next best alternative forgone when a choice is made.

Common Mistake

Writing a long paragraph when the question only asks for a definition.

Keep the response precise.

1. 1State

What It Means

Give a brief answer without detailed explanation.

Example

Question: State one factor that affects the rate of a chemical reaction.

Example answer: Temperature.

The question does not ask you to explain why temperature affects the reaction.

Common Mistake

Adding unnecessary information and potentially introducing an incorrect statement.

1. 1List

What It Means

Give several relevant items without detailed explanation.

Example

Question: List two renewable energy sources.

Example answer:

Solar energy Wind energy

Keep the response direct.

1. 1Describe

What It Means

Give a detailed account of what something is like, what happened, or what can be observed.

Example

Question: Describe the trend shown in the graph.

A strong response should identify the relevant pattern rather than simply saying:

"The graph increases."

A better answer might be:

"The value increases gradually at first and then rises more rapidly as the independent variable increases."

Common Mistake

Explaining why the trend occurs when the question only asks you to describe it.

1. 1Outline

What It Means

Give a brief description of the main points.

Example

Question: Outline two effects of inflation on consumers.

A suitable answer could briefly identify two effects and provide enough detail to demonstrate understanding.

The response should be more developed than a simple list but shorter than a full explanation.

1. 1Explain

What It Means

Give a detailed account of how or why something happens.

Example: Physics

Question: Explain why increasing the resistance in a circuit can reduce current when the potential difference remains constant.

A strong answer should connect the relevant physical relationship to the change in current.

Example: Biology

Question: Explain how enzymes affect reaction rates.

The answer should describe the mechanism and establish the relationship between enzyme activity and reaction rate.

Common Mistake

Giving only a definition.

"An enzyme is a biological catalyst" does not fully answer a question asking you to explain how enzymes affect reaction rates.

1. 1Compare

What It Means

Give an account of the similarities and/or differences between two or more items.

Example

Question: Compare mitosis and meiosis.

A good response should directly compare the processes rather than writing two completely separate descriptions.

For example:

"Both processes involve chromosome replication before cell division, but mitosis produces genetically similar daughter cells, whereas meiosis produces genetically varied cells with half the chromosome number."

Common Mistake

Writing everything about one item and then everything about the other without making the relationship clear.

1. 1Contrast

What It Means

Give an account of the differences between two or more items.

Example

Question: Contrast aerobic and anaerobic respiration.

Focus primarily on differences such as oxygen requirements, energy yield, and products.

Common Mistake

Spending most of the answer describing similarities.

1. 1Analyse

What It Means

Break information into parts and explain relationships, connections, causes, or implications.

This is a higher-level command term than simply describing information.

Example: Economics

Question: Analyse the effect of an increase in interest rates on consumer spending.

A strong answer should establish a logical chain such as:

Higher interest rates → increased borrowing costs → reduced borrowing/spending → possible reduction in aggregate demand.

Then consider relevant conditions or consequences.

Common Mistake

Simply describing what happened without analysing the relationship between the factors.

1. 1Discuss

What It Means

Offer a balanced consideration of different perspectives, arguments, or evidence.

Example

Question: Discuss whether government intervention can reduce income inequality.

A strong answer should consider arguments supporting intervention as well as limitations or counterarguments.

Common Mistake

Writing only one side of the argument.

1. 1Evaluate

What It Means

Make a judgement by considering strengths, weaknesses, evidence, implications, or limitations.

Example

Question: Evaluate the effectiveness of a government policy designed to reduce inflation.

A strong answer should not simply describe the policy.

It should consider:

How the policy works Evidence of its effectiveness Advantages Limitations Possible unintended consequences Relevant conditions Overall judgement

The conclusion should clearly state the extent to which the policy was effective.

Common Mistake

Ending with "therefore, it is effective" without providing enough evidence or reasoning to support the judgement.

1. 1Justify

What It Means

Give valid reasons or evidence supporting a particular conclusion or choice.

Example: Chemistry

Question: Justify the choice of method used in the experiment.

The answer should explain why the chosen method is appropriate and support that reasoning with relevant evidence or scientific principles.

Common Mistake

Simply stating what you chose without explaining why.

1. 1To What Extent

What It Means

Assess how far a statement, argument, or claim is valid.

This command term usually requires a balanced argument followed by a clear judgement.

Example: History

Question: To what extent was economic instability responsible for political change?

A strong answer should:

Examine the role of economic instability. Consider other factors. Compare their relative importance. Reach a reasoned conclusion about the extent. Common Mistake

Giving a simple "yes" or "no" answer without considering the extent.

1. 1Determine

What It Means

Reach a conclusion or answer using available information, calculations, or evidence.

Example: Mathematics

Question: Determine the value of x.

Show the mathematical steps needed to arrive at the answer.

Common Mistake

Giving only the final number when the question requires meaningful working.

1. 1Calculate

What It Means

Obtain a numerical answer using mathematical procedures.

Example: Physics

Question: Calculate the acceleration of the object.

Students should show the relevant calculation, substitute values correctly, and give the final answer with appropriate units where required.

Common Mistake

Using the correct formula but failing to include units or making an avoidable substitution error.

1. 1Deduce

What It Means

Reach a conclusion from information that has been provided.

Example

Question: Deduce the relationship between temperature and reaction rate from the data.

The answer should use the evidence given rather than introducing unrelated information.

1. 1Predict

What It Means

Give an expected outcome based on evidence, patterns, or scientific principles.

Example

Question: Predict what will happen to the reaction rate if the temperature is increased.

A good answer should state the expected outcome and, where appropriate, connect it to the relevant principle.

1. 1Suggest

What It Means

Propose a possible explanation, solution, improvement, or hypothesis.

Example

Question: Suggest one improvement to the experimental method.

The response should propose a realistic improvement and, when appropriate, explain how it could improve reliability or validity.

1. 1Discuss vs Evaluate

These two command terms are often confused.

Discuss

Focus on considering different arguments or perspectives.

Think: "What are the different sides?"

Evaluate

Focus on judging the value, effectiveness, importance, or validity of something.

Think: "How good, effective, important, or valid is it?"

An evaluation normally requires a clear overall judgement supported by reasoning.

1. 1Explain vs Analyse

These terms are also different.

Explain

Focuses mainly on how or why.

Analyse

Goes further by breaking information into components and examining relationships, causes, effects, or implications.

A simple explanation might identify a cause and effect.

An analysis should explore the relationship more deeply and show why it matters.

How to Identify the Command Term in an Exam

When reading an IB question, identify the command term first.

For example:

"Analyse the impact of..."

Think:

Analyse = relationships + evidence + deeper reasoning

If the question says:

"Evaluate whether..."

Think:

Evaluate = evidence + strengths/limitations + judgement

If the question says:

"Compare..."

Think:

Compare = similarities and differences

This simple habit can prevent students from answering at the wrong depth.

A Simple Command-Term Cheat Sheet Command Term What You Should Do Define Give a precise meaning State Give a brief answer List Give several items Describe Give a detailed account Outline Give the main points briefly Explain Show how or why Compare Discuss similarities and/or differences Contrast Focus on differences Analyse Examine relationships and implications Discuss Consider different perspectives Evaluate Weigh evidence and reach a judgement Justify Support a choice or conclusion with reasons Deduce Reach a conclusion from given information Predict State an expected outcome Calculate Work out a numerical answer Determine Find an answer using available information Suggest Propose a possible explanation or solution To what extent Assess how far a claim is valid How Toppers Use Command Terms

High-performing students do not just memorise command-term definitions.

They train themselves to recognise what each term requires when solving real questions.

For example:

Question: "Evaluate the effectiveness of a policy."

Instead of immediately writing, ask:

What does "evaluate" require?

Then build the answer around:

Explanation → Evidence → Advantages → Limitations → Conditions → Judgement

Similarly:

Question: "Analyse the causes of..."

Think:

Cause → Mechanism → Evidence → Consequence → Relationship

This approach makes answers more focused.

Final Thoughts

Understanding IB command terms can improve exam performance because students learn to match their answers to what the question actually requires.

The most important terms to master include:

Explain → Analyse → Compare → Discuss → Evaluate → Justify → To what extent

Do not treat command terms as vocabulary that needs to be memorised once and forgotten. Practise identifying them in real IB questions and deliberately structure your answers around their requirements.

Knowing the content is only part of IB exam success. Knowing what the examiner is asking you to do is equally important.