Exam technique
Command Words
The first word of a question tells you how to earn its marks. Cambridge defines 28 of them for Computer Science; here is each one with what a full-mark answer contains, the mistake that costs the mark and a question stem to recognise it by. Pair it with the glossary and the real past-paper questions, which can be filtered by command word.
Every paper used by O Level / IGCSE and AS & A Level alike — learn these first
- State2210 · 047896181 mark per point
- “express in clear terms”
- Full marks: One precise fact per mark — a name, a value, a term. No explanation is needed and none is credited.
- Loses the mark: Writing a paragraph for a one-word answer wastes time; writing something vague ("it stores data") when a specific term is wanted ("RAM") loses the mark.
- State the denary value of the binary number 01011010.
- Past-paper questions that state
- Give2210 · 047896181 mark per point
- “produce an answer from a given source or recall/memory”
- Full marks: Recall or read off the answer. "Give two examples" wants two distinct items, each different in kind.
- Loses the mark: Giving two examples that are really the same thing ("a mouse and a trackball" for two types of input device) — the second scores nothing.
- Give two benefits of using an interpreter while writing a program.
- Past-paper questions that give
- Identify2210 · 047896181 mark per point
- “name / select / recognise”
- Full marks: Pick out the correct term, component or line — often from a diagram, table or piece of code. Use the exact name.
- Loses the mark: Describing the thing instead of naming it. "The part that does calculations" is not "the ALU".
- Identify the line of pseudocode that contains a syntax error.
- Past-paper questions that identify
- Define2210 · 047896181–2 marks
- “give precise meaning”
- Full marks: The textbook definition, using the key words the mark scheme lists. Learn definitions from the glossary word for word.
- Loses the mark: Using the word in its own definition ("encryption is when data is encrypted") or giving an example instead of a definition.
- Define the term abstraction.
- Past-paper questions that define
- Describe2210 · 047896181 mark per feature, usually 2–4
- “state the points of a topic / give characteristics and main features”
- Full marks: Say what it is and what its main features are — one clear statement per mark. For a process, describe the steps in order.
- Loses the mark: Explaining why (that is a different command word) or listing advantages when the question asked for features.
- Describe how a check digit is used to detect errors in a barcode.
- Past-paper questions that describe
- Explain2210 · 047896182 marks per point, usually 2–6
- “set out purposes or reasons / make the relationships between things clear / say why and/or how, and support with relevant evidence”
- Full marks: Every point needs a reason: make the statement, then add "because…" or "so that…". Marks come in pairs — the point and its justification.
- Loses the mark: A list of statements with no reasons scores half marks at best. "Uses less memory" is a description; "uses less memory because only the changed data is stored" is an explanation.
- Explain why a computer needs both RAM and ROM.
- Past-paper questions that explain
- Outline2210 · 047896181 mark per point
- “set out the main points”
- Full marks: The headline points only, in a logical order — a brief description without detail or justification.
- Loses the mark: Going into depth on the first point and running out of space for the others. Breadth beats depth here.
- Outline the stages of the fetch–decode–execute cycle.
- Past-paper questions that outline
- Compare2210 · 047896181 mark per comparison
- “identify / comment on similarities and/or differences”
- Full marks: Each point must mention both things: "A does X whereas B does Y". Cover similarities and differences unless the question limits you to one.
- Loses the mark: Describing A in one paragraph and B in another leaves the examiner to make the comparison — no marks for points that name only one side.
- Compare serial and parallel data transmission.
- Past-paper questions that compare
- Calculate2210 · 047896181–3 marks (working + answer)
- “work out from given facts, figures or information”
- Full marks: Show every step and give the answer with its unit. Working can earn marks even if the final figure slips.
- Loses the mark: Writing only the final answer — one arithmetic error then costs every mark. Forgetting units (bytes vs bits, MiB vs MB).
- Calculate the file size of a 20-second sound file sampled at 44 100 Hz with a sample resolution of 16 bits.
- Past-paper questions that calculate
- Demonstrate2210 · 047896181–3 marks
- “show how or give an example”
- Full marks: Prove the point with a worked example or a concrete case — code, a trace, a diagram, a calculation.
- Loses the mark: Asserting that something is true without showing it happening.
- Demonstrate, using an example, how a logical shift can be used to multiply a binary number by 2.
- Past-paper questions that demonstrate
- Evaluate2210 · 047896184–8 marks
- “judge or calculate the quality, importance, amount, or value of something”
- Full marks: Weigh the strengths and weaknesses and finish with a judgement that follows from them. The conclusion is a marking point of its own.
- Loses the mark: Listing pros and cons and stopping. Without a reasoned verdict the top mark is out of reach.
- Evaluate the use of biometrics as the only method of authentication for a school's network.
- Past-paper questions that evaluate
- Suggest2210 · 047896181–2 marks per point
- “apply knowledge and understanding to situations where there are a range of valid responses in order to make proposals / put forward considerations”
- Full marks: There is more than one right answer. Propose something sensible for the scenario given and, if asked, say why it fits.
- Loses the mark: Suggesting something generic that ignores the scenario ("use a sensor" when the question needs a specific sensor for a greenhouse).
- Suggest two sensors the greenhouse system could use, giving a reason for each.
- Past-paper questions that suggest
O Level / IGCSE only printed in the 2210 / 0478 syllabus
- Show (that)2210 · 04782–3 marks
- “provide structured evidence that leads to a given result”
- Full marks: The answer is already in the question — the marks are for the steps that get there. Lay the working out in order.
- Loses the mark: Writing the given result and nothing else.
- Show that the hexadecimal value 3F is 63 in denary.
- Past-paper questions that show (that)
AS & A Level only the extra verbs 9618 Papers 1–4 use
- Write96183–8 marks (algorithms) or more (Paper 4 code)
- “write an answer in a specific way”
- Full marks: Write the pseudocode, program code, SQL or assembly the question asks for — in exactly the form it specifies. Declare variables, use the given identifiers, meet every bullet point.
- Loses the mark: Writing pseudocode when program code was asked for (or the reverse); ignoring an identifier the question told you to use; missing a bullet point.
- Write pseudocode for the function CountVowels() that takes a string and returns the number of vowels in it.
- Past-paper questions that write
- Complete96181 mark per entry or row
- “add information to an incomplete diagram or table”
- Full marks: Fill every gap — trace-table rows, truth-table columns, missing pseudocode lines, mark-scheme grids.
- Loses the mark: Leaving a cell blank. A guess can score; an empty cell never does.
- Complete the trace table for the algorithm when the input is 6.
- Past-paper questions that complete
- Draw96181 mark per correct line
- “draw a line to match a term with a description”
- Full marks: One line from each term to one description. Use a ruler if it helps; make each line unambiguous.
- Loses the mark: Drawing two lines from one term "to be safe" — that cancels the mark.
- Draw one line from each network device to its description.
- Past-paper questions that draw
- Analyse96183–6 marks
- “examine in detail to show meaning, identify elements and the relationship between them”
- Full marks: Break the situation into its parts, say what each part does and how the parts affect each other.
- Loses the mark: Retelling the scenario instead of taking it apart.
- Analyse the effect of increasing the page size on the performance of a virtual memory system.
- Past-paper questions that analyse
- Assess96183–6 marks
- “make an informed judgement”
- Full marks: Judge how good, effective or suitable something is, giving evidence for the judgement.
- Loses the mark: Judging without evidence, or giving evidence without a judgement.
- Assess the suitability of a bus topology for a network of 200 workstations.
- Past-paper questions that assess
- Comment96181–3 marks
- “give an informed opinion”
- Full marks: Say what you think and back it with a relevant point of knowledge.
- Loses the mark: An opinion with no computing behind it.
- Comment on the choice of a linked list for storing the print queue.
- Past-paper questions that comment
- Consider96182–4 marks
- “review and respond to given information”
- Full marks: Read the given information carefully and respond to it specifically — the marks depend on using what you were given.
- Loses the mark: Answering from memory and never referring to the information in the question.
- Consider the program design shown. Identify a more appropriate data structure for the marks and justify your choice.
- Past-paper questions that consider
- Contrast96181 mark per difference
- “identify / comment on differences”
- Full marks: Differences only, each stated for both items: "a compiler produces object code whereas an interpreter does not".
- Loses the mark: Including similarities — they earn nothing here.
- Contrast the roles of the lexical analysis and syntax analysis stages of compilation.
- Past-paper questions that contrast
- Develop96182–6 marks
- “take forward to a more advanced stage or build upon given information”
- Full marks: Start from what is given (a design, an algorithm, an argument) and extend or improve it.
- Loses the mark: Starting again from scratch instead of building on the given material.
- Develop the pseudocode so that the search stops as soon as the item is found.
- Past-paper questions that develop
- Discuss96184–8 marks
- “write about issue(s) or topic(s) in depth in a structured way”
- Full marks: A structured answer with more than one viewpoint: points for, points against, and a reasoned conclusion. Use paragraphs.
- Loses the mark: One-sided answers, or bullet points with no development.
- Discuss the ethical issues raised by the use of AI to shortlist job applicants.
- Past-paper questions that discuss
- Examine96183–6 marks
- “investigate closely, in detail”
- Full marks: Look closely at how something works or what it implies, with detail at every step.
- Loses the mark: A surface-level overview.
- Examine how pipelining improves the throughput of a processor.
- Past-paper questions that examine
- Justify96181–3 marks
- “support a case with evidence / argument”
- Full marks: Give the reasons that support the choice or statement — specific, technical reasons tied to the scenario.
- Loses the mark: Restating the choice ("a stack is best because it is a stack").
- Justify the use of a stack when evaluating a Reverse Polish expression.
- Past-paper questions that justify
- Predict96181–2 marks
- “suggest what may happen based on available information”
- Full marks: Use the information given to say what will happen and, if asked, why.
- Loses the mark: Guessing without reference to the data in the question.
- Predict the output of the program when the input is –1.
- Past-paper questions that predict
- Sketch96182–3 marks
- “make a simple freehand drawing showing the key features, taking care over proportions”
- Full marks: A neat, labelled drawing that shows the essentials — a diagram, a tree, a circuit — not a work of art.
- Loses the mark: Missing labels. An unlabelled sketch can be impossible to credit.
- Sketch the binary tree produced when the values 50, 30, 70, 20, 40 are inserted in that order.
- Past-paper questions that sketch
- Summarise96182–3 marks
- “select and present the main points, without detail”
- Full marks: The key points only, in your own words, briefly.
- Loses the mark: Copying detail from the question or writing at length.
- Summarise the purpose of the transport layer in the TCP/IP protocol suite.
- Past-paper questions that summarise
Definitions follow the command-word tables in the Cambridge O Level 2210 / IGCSE 0478 (2026–2028) and AS & A Level 9618 (2027–2029) syllabuses; the guidance is ZAK's. Command words are © Cambridge Assessment International Education.