Command Words and Mark Schemes

Every exam question opens with a command word — state, describe, explain, calculate, evaluate — and that word is an instruction telling you exactly what kind of answer to give and how much to write. Misreading it is one of the most expensive mistakes in the exam: a student who describes when asked to explain, or who gives an answer without calculating, throws away marks their knowledge had earned. Understanding command words, and how mark schemes turn your answer into marks, lets you give the examiner precisely what they are looking for.

By the end of this lesson you should know the main OCR command words and what each demands, understand how point-marked and levels-marked schemes award marks, and know why showing your working is essential.

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The Main OCR Command Words

Command word	What it demands	Typical marks
State / Give / Name	A short factual answer — a word, value or phrase. No explanation.	1
Describe	Say what happens or what something is like — the features or the steps. No why.	2–4 (or 6)
Explain	Give reasons — say why or how, using "because"/"so".	2–4 (or 6)
Calculate	Work out a numerical value, showing working, with a unit.	2–4
Determine	Use given data/a graph to find a value (often calculate from something).	2–4
Evaluate	Weigh advantages and disadvantages (or the evidence) and give a conclusion.	4–6
Compare	Give similarities and differences, referring to both things.	2–4
Suggest	Apply your knowledge to an unfamiliar situation — a sensible, reasoned idea.	1–3

The single most important distinction is describe vs explain. Describe wants the what; explain wants the why. "The current increases as the voltage increases" is a description; "the current increases because a greater potential difference pushes more charge through the component each second" is an explanation. If you only describe when asked to explain, you cap your marks.

Exam Tip: Learn the describe vs explain split cold. Describe = what happens (the observation or steps). Explain = why it happens (reasons, mechanisms, using "because" and "so"). Mixing them up is the commonest way students lose marks they clearly knew.

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What Each Command Word Looks Like in Physics

• State the unit of frequency. → Hertz (Hz). (One word — no more needed.)
• Describe the motion shown by the graph. → The object moves at constant speed, then decelerates to rest. (What happens.)
• Explain why the filament lamp's resistance increases. → As current increases the filament heats up, so the metal ions vibrate more and impede the flow of electrons, increasing resistance. (Why — a chain.)
• Calculate the power given current and p.d. → $P = IV = 2 \times 12 = 24$P=IV=2×12=24 W. (Value, working, unit.)
• Evaluate the use of wind power. → Advantages... disadvantages... overall conclusion. (Both sides + judgement.)
• Suggest why the reading was too high. → A reasoned idea applied to that experiment (e.g. heat was lost to the surroundings).

Notice how the length and shape of the answer follow directly from the command word — a "state" gets one word, an "explain" gets a linked chain, an "evaluate" gets a balanced argument with a conclusion.

Exam Tip: Let the command word set your answer length. Do not write a paragraph for a "state" (you waste time), and do not write one line for an "explain" worth 3 marks (you lose marks). Match the effort to the word and the tariff.

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How Point-Marked Schemes Work

Most short and medium questions are point-marked: the mark scheme lists creditable points, and you earn one mark for each one you make (up to the tariff). Key features:

• The number of marks tells you how many points to give. A 3-mark "explain" wants three distinct creditable statements.
• Mark schemes often list more points than the tariff — you do not need all of them, just enough. This is your safety net: make an extra point if unsure.
• Schemes use "allow" (acceptable alternative wording) and "do not allow" (answers that miss the point) — so there is usually more than one way to phrase a correct answer, but vague answers are explicitly excluded.
• Some points are marked "ORA" (or reverse argument) — the opposite statement also earns credit.

flowchart LR
    A[Question tariff, e.g. 3 marks] --> B[Give 3 distinct creditable points]
    B --> C[Mark scheme lists points]
    C --> D[allow: alternative wording]
    C --> E[do not allow: vague answers]
    D --> F[1 mark per valid point]
    E --> F

Exam Tip: Read the mark tariff as a checklist. Three marks = three separate points. Before moving on, count the distinct ideas in your answer against the number in the brackets — if you have written two points for a 3-mark question, you know to add one more.

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How Levels-Marked Schemes Work

The six-mark extended-response questions use a levels-of-response scheme instead of points (covered fully in the six-mark lesson). Briefly: your whole answer is read and placed in Level 1 (1–2), Level 2 (3–4) or Level 3 (5–6) according to how detailed, coherent and well-linked it is, and whether it uses correct terminology. Here the quality of the argument matters as much as the individual facts.

Exam Tip: For point-marked questions, think "how many separate points?"; for levels-marked (6-mark) questions, think "how well-linked and complete is my whole argument?". The two schemes reward different things — a list can score full marks on a point-marked question but only Level 2 on a levels-marked one.

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Reading a Point-Marked Scheme in Detail

It is worth seeing exactly how a point-marked scheme turns your words into marks, because understanding the mechanism changes how you write. Take a 4-mark question: "Explain why a metal wire gets warm when a current flows through it." A typical mark scheme would list creditable points such as: (1) the current is a flow of electrons; (2) the electrons collide with the metal ions as they move; (3) these collisions transfer energy to the ions, which vibrate more; (4) this raises the temperature of the wire (increases the thermal energy store). Each numbered point is worth one mark, and you earn four by making four of the listed ideas. The scheme will also carry conditions: it may allow "atoms" as an alternative to "ions", but not allow the vague "the electricity heats it up", which restates the question without explaining it.