Computer Science

AQA

GCSE

Specification: 8525

Computer Science develops your understanding of how computers work and how to program them effectively. You'll learn algorithms, data structures, systems architecture and develop practical programming skills.

Topics

Objectives

Exam Tips

Pitfalls

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Study Guides

2 revision guides for AQA GCSE Computer Science

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Key Features

Write and debug programs
Design efficient algorithms
Understand computer systems
Develop computational thinking

Assessment Objectives

AO1

30%

Demonstrate knowledge and understanding of the key concepts and principles of computer science

AO2

40%

Apply knowledge and understanding of key concepts and principles of computer science

AO3

30%

Analyse problems in computational terms: • to make reasoned judgements • to design, program, evaluate and refine solutions

What Gets Top Grades

A*/Grade 9

Knowledge & Understanding

Demonstrates comprehensive and accurate knowledge

Uses correct subject-specific terminology
Shows detailed understanding of concepts
Makes accurate connections between topics
Demonstrates depth beyond surface-level knowledge

Application

Applies knowledge effectively to new contexts

Selects relevant knowledge for the question
Adapts understanding to unfamiliar scenarios
Uses examples appropriately
Shows awareness of context

Analysis & Evaluation

Develops sophisticated analytical arguments

Constructs logical chains of reasoning
Considers multiple perspectives
Weighs evidence to reach justified conclusions
Acknowledges limitations and nuances

Key Command Words

AQA

State

1 mark

Give a single fact or term

Identify

1 mark

Name, select, or recognise

Outline

2 marks

Set out main features briefly

Describe

2-4 marks

Give an account of what something is like or what happens

Explain

3-6 marks

Give reasons with developed cause→effect chains

Compare

2-4 marks

State similarities AND differences (both required)

Analyse

6-9 marks

Examine in detail showing cause→effect→consequence chains

Evaluate

6-12 marks

Weigh up BOTH sides, reach JUSTIFIED conclusion

Assess

6-12 marks

Make judgments about importance with justification

Calculate

2-4 marks

Show formula→substitution→calculation→answer with units

Common Exam Mistakes

Pitfalls to avoid in your exams

•Stating the Program Counter holds the *current* instruction's address rather than the *next* one
•Confusing the Memory Address Register (MAR) with the Memory Data Register (MDR) when describing data transfer
•Asserting that doubling the number of cores automatically doubles processing speed, ignoring software optimization or sequential task limitations
•Describing the CPU as 'thinking' or using anthropomorphic language instead of 'processing' or 'executing'
•Stating that the entire Operating System is stored in ROM (it is stored in secondary storage and loaded into RAM upon boot).
•Confusing 'memory' (RAM) with 'secondary storage' (HDD/SSD), incorrectly implying that files saved in RAM are permanent.
•Asserting that adding more RAM increases the processing speed (clock speed) of the CPU, rather than explaining it reduces reliance on slower virtual memory.
•Describing ROM as 'random access' simply because it is memory; candidates must treat it as distinct from RAM in terms of access capability.

Top Examiner Tips

Expert advice for exam success

•When describing the Fetch-Execute cycle, explicitly mention the transfer of data between specific registers (e.g., 'PC to MAR') rather than just saying 'data moves'.
•For performance questions, distinguish between 'Clock Speed' (cycles per second) and 'Core Count' (independent processing units).
•Memorise the full names of registers; using acronyms (MAR, MDR) is acceptable only if you are precise with their distinct functions.
•Always use the specific terms 'volatile' and 'non-volatile' instead of colloquial phrases like 'forgets data' or 'keeps data'.
•When justifying why a computer needs more RAM, explicitly mention 'reducing the need for virtual memory' to secure AO2 application marks.
•In comparison questions, structure your answer to contrast volatility, content (current programs vs. BIOS), and editability (Read/Write vs. Read-Only) side-by-side.
•Memorize the six characteristics (Capacity, Speed, Portability, Durability, Reliability, Cost) and use them as headings to structure 'Compare' or 'Justify' answers
•When asked to recommend a device, always link the characteristic directly to the scenario (e.g., 'The action camera needs an SSD because it is durable against vibrations')