0478 · Cambridge IGCSE
0478/21
Algorithms, Programming and Logic
Computer Science · June 2025 · Variant 1
Relative difficulty
Analysis source: Cambridge Assessment International Education
Analysis aligned to the official syllabus and assessment design.
3.5 / 5
150
210 min
Programming Concepts & Control Structures
Cohort performance
Session statistics from official examination reports
Total marks
150
Duration
210 min
Session difficulty
3.5 / 5
Key examiner messages
Top priorities from the principal examiner before you revise
The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment.
Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty level.
However, Paper 2 (Algorithms, Programming and Logic) steps up the challenge with high-level logic tracing and a detailed 15-mark multi-dimensional array problem.
Consequently, the series carries an overall difficulty rating of 4 stars (3.5/5).
Question difficulty map
How candidates performed on each question in this series
No data available in official reports
Assessment objectives
Skill and AO weighting from official examiner commentary
Skill weighting
Shows the skill mix this paper tested most heavily.
Technical
Weight: 7100%Recall
Weight: 686%Computational
Weight: 571%Pseudocode &
Weight: 457%Representation Logical
Weight: 343%Problem A
Weight: 114%
Method marks watchlist
Where working, steps, or method marks were commonly lost
No data available in official reports
Recurring mistakes across years
Themes examiners flag in multiple recent sessions for this subject
No data available in official reports
Question choice intelligence
Mean scores and popularity for optional questions (HKDSE electives)
No data available in official reports
Level exemplars
What candidate scripts at each grade level looked like
No data available in official reports
Grade & admission context
How marks relate to grade thresholds and entry standards
Report type
Cambridge Principal Examiner Report — component performance and international standards
Level A*
Approx. 77% of maximum mark
Level A
Approx. 63% of maximum mark
Level B
Approx. 48% of maximum mark
Level C
Approx. 33% of maximum mark
Level D
Approx. 28% of maximum mark
Level E
Approx. 23% of maximum mark
Deep insights
What top candidates did
Techniques and approaches examiners rewarded in this series
No data available in official reports
Command word playbook
How to match each command word to the expected response style
Give reasons and link mechanism to outcome; each point needs a because/so chain.
State features in sequence or list observable properties — do not explain causes unless asked.
Match the expected response style for “State” questions.
Match the expected response style for “Give” questions.
Name or point to the specific feature asked for — avoid extra explanation.
Match the expected response style for “Write” questions.
Match the expected response style for “Convert” questions.
Time traps
Sections where candidates spent disproportionate time relative to marks
Min per mark: 2
Min per mark: 1.3
Syllabus traceability
Topics linked to questions and mark weighting in this session
Programming concepts
26 marks this session
Algorithm design and problem-solving
19 marks this session
Arrays
15 marks this session
Data storage
11 marks this session
MCQ trap analytics
Commonly chosen wrong options from examiner commentary
No data available in official reports
Topic heatmap across years
Mark concentration by topic and exam year for this subject
Mark intensity
Algorithm design and problem-solving
Programming concepts
Arrays
Cyber security
Robotics
Methods of error detection
The internet and the world wide web
Data storage
Difficulty trend
How session difficulty has shifted across recent years
Paper comparison
Marks and duration breakdown across papers in this session
Paper 1 Computer Systems:
Paper 2 Algorithms, Programming and Logic:
Marks you can still earn
Where valid approaches outside the mark scheme may still gain credit
No data available in official reports
Practise what examiners flagged
Target weak topics from this report inside the Revui app
Programming concepts
26 marks this session
Practise in RevuiAlgorithm design and problem-solving
19 marks this session
Practise in RevuiArrays
15 marks this session
Practise in RevuiData storage
11 marks this session
Practise in RevuiSelf-diagnostic checklist
Key actions before you sit this paper — copy and tick off as you revise
- 1Message
The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment.
- 2Message
Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty level.
- 3Message
However, Paper 2 (Algorithms, Programming and Logic) steps up the challenge with high-level logic tracing and a detailed 15-mark multi-dimensional array problem.
- 4Message
Consequently, the series carries an overall difficulty rating of 4 stars (3.5/5).
Teacher briefing pack
One-page session summary for tutors and classroom review
June 2025 2025
Computer Science
The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment. Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty le
The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment.
Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty level.
However, Paper 2 (Algorithms, Programming and Logic) steps up the challenge with high-level logic tracing and a detailed 15-mark multi-dimensional array problem.
- Total marks
- 150
- Duration
- 210 min
- Session difficulty
- 3.5 / 5
Session analysis
The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment. Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty level. However, Paper 2 (Algorithms, Programming and Logic) steps up the challenge with high-level logic tracing and a detailed 15-mark multi-dimensional array problem. Consequently, the series carries an overall difficulty rating of 4 stars (3.5/5).
Updated Jun 13, 2026
Paper breakdown
Paper 1 Computer Systems:
Paper 2 Algorithms, Programming and Logic:
Top chapters
Exam structure insights
Marks by chapter
See where the marks were concentrated so revision time goes to the highest-value topics.
Mark accessibility
Estimate which marks were basic, mid-level, or high-difficulty.
80% within easy or medium reach
Command word frequency
Spot common command words so answers match the expected response style.
Question type mix
Compare the mark share of each paper section and question type.
Descriptive/Essay
47·12·31%
Short Answer
38·20·25%
Algorithms & Pseudocode
37·6·25%
Scenario-based Programming
15·1·10%
Logic & Truth Tables
8·2·5%
Data Conversions & SQL
5·3·3%
Study ROI
Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.
Time vs marks
Compare marks with suggested time allocation to plan exam pacing.
Paper 1: Core Syste…
0.80 m/minPaper 2: Section A …
0.50 m/minTotal marks
75
Total time
105 min
Avg pace
0.71
Next-year prediction
Topics worth watching next year, with the reason shown directly below each bar.
File Handling in Pseudocode
90%90%
Automated Systems (Sensors & Actuators)
85%85%
Types of Language Translators (Compilers/Interpreters/Assemblers)
80%80%
Overall Difficulty Verdict
The May/June 2025 examination series for Cambridge IGCSE Computer Science (0478) presents a balanced yet rigorous assessment. Paper 1 (Computer Systems) leans on classic, structured explanations of technical hardware and transmission concepts, maintaining a moderate difficulty level. However, Paper 2 (Algorithms, Programming and Logic) steps up the challenge with high-level logic tracing and a detailed 15-mark multi-dimensional array problem. Consequently, the series carries an overall difficulty rating of 4 stars (3.5/5).
Examiner notes & key calculations
- Logic Tracing Confusion: In the grade calculation flowchart, many candidates struggled to notice the logical flaw where the check IS Score >= 40 ? occurred first. This led to incorrect tracing outputs as subsequent thresholds were bypassed.
- Syntax in Pseudocode: Candidates frequently lost marks on the 15-mark programming question by mixing up 1D and 2D array indexing, failing to validate inputs to the exact 0 TO 100 range, or neglecting to reset maximum value trackers correctly before search loops.
- Asymmetric Encryption Vocabulary: The cloze passage on asymmetric encryption tested precise terminology, where mixing up public and private key roles in encryption/decryption was a common mistake.
Exam tips
Paper format
- Duration
- 1h 45min
- Total marks
- 75
- Weighting
- 50%
- Question types
- Trace tables & Diagrams, Pseudocode writing, Scenario-based coding (2D Array), SQL and Database tasks
Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.