Command terms
The official IB command terms for chemistry, grouped by assessment objective, with verbatim definitions so you know exactly what each question is asking.
The guide states: “These command terms indicate the depth of treatment required.”
Assessment objective 1 — Demonstrate knowledge
- Draw
- Represent by means of a labelled, accurate diagram or graph, using a pencil. A ruler (straight edge) should be used for straight lines. Diagrams should be drawn to scale. Graphs should have points correctly plotted (if appropriate) and joined in a straight line or smooth curve.
- State
- Give a specific name, value or other brief answer without explanation or calculation.
Assessment objective 2 — Understand and apply knowledge
- Annotate
- Add brief notes to a diagram or graph.
- Calculate
- Obtain a numerical answer showing the relevant stages in the working.
- Describe
- Give a detailed account.
- Estimate
- Obtain an approximate value.
- Outline
- Give a brief account or summary.
- Identify — from IA descriptor table, not the main glossary
- Provide an answer from a number of possibilities.
Assessment objective 3 — Analyse, evaluate and synthesise
- Comment
- Give a judgement based on a given statement or result of a calculation.
- Compare
- Give an account of the similarities between two (or more) items or situations, referring to both (all) of them throughout.
- Contrast
- Give an account of the differences between two (or more) items or situations, referring to both (all) of them throughout.
- Deduce
- Reach a conclusion from the information given.
- Determine
- Obtain the only possible answer.
- Discuss
- Offer a considered and balanced review that includes a range of arguments, factors or hypotheses. Opinions or conclusions should be presented clearly and supported by appropriate evidence.
- Evaluate
- Make an appraisal by weighing up the strengths and limitations.
- Explain
- Give a detailed account including reasons or causes.
- Predict
- Give an expected result.
- Sketch
- Represent by means of a diagram or graph (labelled as appropriate). The sketch should give a general idea of the required shape or relationship, and should include relevant features.
- Justify — from IA descriptor table, not the main glossary
- Give valid reasons or evidence to support an answer or conclusion.
Terms that appear in the syllabus but are NOT in the 2025 glossary
These terms appear in the syllabus skill statements but are notdefined command terms in the 2025 guide’s glossary. Do not treat them as defined command terms:
- Define
- Distinguish
- Apply
- Derive
- Formulate
- Construct
- Interpret
- Analyse
- Recognize
- Solve
- Convert
- Perform
Notes
- The 2025 guide’s glossary is notably shorter than the pre-2025 guide’s.
- Only Compare and Contrastare separate terms; “compare and contrast” also occurs in practice.
- There is no “Define” in the 2025 glossary.
- Identify and Justify are listed in the IA descriptor table but not in the main glossary. Confirm whether IB treats them as full command terms for examination purposes.