“Explain” — what the examiner wants
How to answer a Cambridge Computer Science question that starts with Explain (2210, 0478 & 9618): Cambridge's definition, what a full-mark answer contains, the mistake that loses the mark, and how often the word has come up in 380 current-syllabus past-paper questions.
Cambridge's definition
“set out purposes or reasons / make the relationships between things clear / say why and/or how, and support with relevant evidence”
What earns 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.
What 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.
A question that uses it
Explain why a computer needs both RAM and ROM.
In real past papers
Current-syllabus questions only (2210 / 0478 from 2023, 9618 from 2021); a question set under both 2210 and 0478 counts once.
380
questions
464
parts open with it
3
median marks a part
By paper
- 2210 / 0478 Paper 187 of 210 questions · 41%
- 2210 / 0478 Paper 233 of 262 questions · 13%
- 9618 Paper 1120 of 270 questions · 44%
- 9618 Paper 247 of 251 questions · 19%
- 9618 Paper 393 of 353 questions · 26%
Typical marks per part: 2 marks (34%), 3 marks (33%), 4 marks (23%), 1 mark (4%).
Topics where “Explain” comes up most
Recent questions that use it
Open any one to read it and mark your answer against the official mark scheme.
Marks shown as “a / b”: a = marks in parts that open with “Explain”, b = the whole question.
Don't confuse it with
The definition follows the command-word table in the Cambridge syllabus; the guidance is ZAK's. Statistics come from the real past-paper question bank (command words are read from each question's wording). Command words and past papers are © Cambridge Assessment International Education.