IB Economics SLTopic 5 — Assessment and Exam SkillsAll papersExam skill~8 min read
The Skills Every Answer Should Show
Behind every IB Economics question sit four skills, called assessment objectives. You never see them printed on the paper. You see a command term instead, and the command term is the signal telling you which skill the examiner wants most. Read that signal correctly and you stop writing the wrong kind of answer.
📘 What you need to know
There are four assessment objectives: AO1 knowledge and understanding, AO2 application and analysis, AO3 synthesis and evaluation, AO4 use and application of skills.
AO1 to AO3 get harder as you go up. AO4 is different — it is the technical work (diagrams, calculations, data) that sits under all of them.
Command terms tell you which skill leads. “Define” is AO1. “Explain” is AO2. “Evaluate” is AO3. “Calculate” is AO4.
Most questions want more than one skill at once. A 15-mark answer can use all four.
Without accurate AO1, nothing above it can be rewarded — wrong theory cannot be well applied.
AO2 matters most where there is a stimulus to apply theory to, which means Paper 2 above all.
The AOs tell you how much to write, whether a diagram or calculation is wanted, and how much evaluation is needed.
The four skills, stacked
The first three are a ladder. You have to know the economics before you can apply it, and you have to apply it before you can judge it. The fourth one is not a step on that ladder at all; it is the technical accuracy running underneath, and it can quietly cost you marks on any question.
You cannot apply theory you have got wrong, and you cannot evaluate an argument you have not built. That is why a vague definition damages a long answer, not just a short one.
Paper 3 is a Higher Level paper only. If you see AO advice that mentions Paper 3, it does not apply to you at SL. Your AOs are tested through Paper 1 and Paper 2 only.
What each skill actually means
AO1: knowledge and understanding
Showing that you know the economics. Precise definitions, clear explanations of concepts and theories, and the right vocabulary all the way through. It is most obvious in short questions, but it holds up every other answer. Say “quantity demanded falls” rather than “people buy less”, because the first one is economics and the second one is a comment.
A vague definition does more damage than students expect. If your definition of inflation is loose, the examiner cannot be sure your later analysis is right, so the analysis marks get held back too.
AO2: application and analysis
Using economics here, in this situation, with this data. It means taking theory to a real case, pulling information out of a text, table, graph or diagram, and explaining how the concept works in the specific situation you have been given. Theory that never touches the context cannot score well, however correct it is.
AO3: synthesis and evaluation
Thinking like an economist: building an argument, putting theory and evidence together, looking at more than one perspective, and reaching a balanced judgement. Evaluation is not opinion. “I think subsidies are good” is opinion. “The subsidy raises output but the cost falls on taxpayers, and with inelastic demand most of it ends up with producers” is evaluation, because reasoning and evidence sit underneath it.
AO4: use and application of skills
The technical layer. Drawing and labelling diagrams accurately, doing calculations correctly, reading numbers and graphs properly, and organising your answer so it can be followed. These are the easiest marks on the paper and the ones most often thrown away, usually through a missing label, a missing unit or a rounding slip.
Command terms: the signal in the question
Command terms are sorted by AO, so the term is a direct instruction about what kind of answer to write. Learn the four families and you will never again write a definition when the paper wanted a judgement.
Skill
What the examiner wants
Command terms that signal it
AO1
Show you know the economics
define, list, state, describe, outline
AO2
Use it in this context or this data
explain, analyse, comment on, distinguish, apply
AO3
Weigh it up and reach a judgement
discuss, evaluate, examine, to what extent, justify, recommend
AO4
Get the technical work right
calculate, draw, sketch, label, plot, derive, determine, show
The rule that saves the most marks
the command term sets the skill → the skill sets the shape of the answer → the marks set the length
WORKED EXAMPLE
The same topic, asked three ways. What changes each time?
“Define the term price ceiling. [2]”
AO1. One accurate sentence, correct terminology, then stop.
“Explain, using a diagram, how a price ceiling affects the market for rented housing. [4]”
AO2 with AO4. Labelled diagram, then a chain: ceiling below equilibrium → quantity demanded exceeds quantity supplied → shortage.
“Evaluate the use of price ceilings in the rental market. [15]”
AO3 leading, held up by AO1, AO2 and AO4. Theory, both sides, a real example, then a judgement with a reason.
Same content, three different answersThe economics barely changes. What changes is how much of it you use and what you do with it.
How the four work together
Most questions test several skills at once. A 15-mark question can reasonably want all four: the definitions (AO1), the application to the case (AO2), the evaluation (AO3) and a correctly labelled diagram (AO4). The command term tells you which one leads; the others support it.
Read your own answer back and ask which layers are actually present. It is the fastest self-check there is.
🧩 Decoding a question in 30 seconds
Find the command term. Usually the first word. Circle it.
Name the AO it belongs to. Define is AO1, explain is AO2, evaluate is AO3, calculate is AO4.
Look at the marks. They tell you how many developed points are wanted.
Check for AO4 words. “Using a diagram”, “calculate”, “refer to the table” are instructions, not suggestions.
Decide the shape before writing: how many paragraphs, diagram or no diagram, judgement or no judgement.
WORKED EXAMPLE
Decode this: “Using information from Table 2, explain how rising unemployment may affect government spending. [4]”
Step 1: the command term
“Explain” → AO2 leads. This wants a chain of reasoning applied to the situation.
Step 2: the hidden instruction
“Using information from Table 2” is AO4 and AO2 together. A figure from Table 2 must appear in the answer.
Step 3: the marks
4 marks means one or two developed points, not an essay, and no evaluation.
Step 4: the shape
One short paragraph: theory chain, one figure from the table, the effect on spending.
AO2 leading, AO4 required, no AO3Writing “however, it depends on the size of the deficit” here earns nothing. The question never asked for judgement.
💡 Exam tip
Match the verb to the answer. If your answer would be the same for “define” and “evaluate”, something has gone wrong.
Treat terminology as free marks. “Contraction in quantity supplied” and “decrease in supply” are different things, and examiners notice.
Underline the AO4 instructions. “Using a diagram” and “calculate” are the easiest marks and the easiest to miss.
Evaluation needs a reason attached. Every “however” should be followed by economics, not by a feeling.
Check the layers before you move on: did I define, did I apply, did I judge, is the technical work clean?
Learn the command terms as families, not as a list of twenty words. Four groups is much easier to hold in your head.
⚠️ Common mix-up
Treating evaluation as opinion. AO3 is reasoning and evidence, not what you personally prefer.
Explaining theory and calling it application. AO2 needs the context in the sentence, not just in the question.
Ignoring AO4 because it feels minor. Missing labels, wrong units and early rounding are pure lost marks.
Adding evaluation to a low-mark question. It earns nothing there and eats time you need elsewhere.
Using “explain” and “describe” as if they mean the same. Describe says what happens; explain says why it happens.
Assuming a big question needs only the top skill. A 15-mark answer without definitions or a diagram is missing layers it should have.
Up next: Writing a Strong 4-Mark Answer — the shortest question type that still needs a proper chain of reasoning, and where AO2 and AO4 meet.
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