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COMPUTER-SCIENCE · Pearson Edexcel IGCSE

COMPUTER-SCIENCE/21

Application of Computational Thinking

Computer Science · 2023 · Variant 1

Relative difficulty

Demanding · 3.8/5

Analysis source: Pearson Edexcel

Analysis aligned to the official syllabus and assessment design.

Relative difficulty

3.8 / 5

Total marks

160

Duration

300 min

Most tested topic

Practical software development and algorithm execution

Cohort performance

Session statistics from official examination reports

Total marks

160

Duration

300 min

Session difficulty

3.8 / 5

Key examiner messages

Top priorities from the principal examiner before you revise

1

The Summer 2023 Pearson Edexcel International GCSE Computer Science examination provided a balanced yet challenging test of candidates' skills across both papers.

2

Paper 1 (Principles of Computer Science) evaluated core academic and theoretical elements, while Paper 2 (Application of Computational Thinking) put practical coding and debugging proficiency under the microscope.

3

Feedback from the Principal Examiner reveals a widening gap between students who possess superficial knowledge and those who can apply computer science concepts in concrete contexts.

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

Theoretical Recall9
Mathematical & Calculation7
Algorithmic Analysis6
Practical4
Softwar3
Critical Discussion2

Skill weighting

Shows the skill mix this paper tested most heavily.

Theoretical RecallTheoreticalRecallMathematical & CalculationMathematical &CalculationAlgorithmic AnalysisAlgorithmicAnalysisPracticalPracticalSoftwarSoftwarCritical DiscussionCriticalDiscussion
SkillWeightShare
  • Theoretical Recall

    Weight: 9100%
  • Mathematical & Calculation

    Weight: 778%
  • Algorithmic Analysis

    Weight: 667%
  • Practical

    Weight: 444%
  • Softwar

    Weight: 333%
  • Critical Discussion

    Weight: 222%

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

Examiner report — national grade boundaries and question-level commentary

Level 9

Approx. 83% of maximum mark

Level 8

Approx. 77% of maximum mark

Level 7

Approx. 71% of maximum mark

Level 6

Approx. 61% of maximum mark

Level 5

Approx. 53% of maximum mark

Level 4

Approx. 44% of maximum mark

Level 3

Approx. 32% of maximum mark

Level 2

Approx. 20% 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

StateFrequency: 7

Match the expected response style for “State” questions.

DescribeFrequency: 10

State features in sequence or list observable properties — do not explain causes unless asked.

ExplainFrequency: 4

Give reasons and link mechanism to outcome; each point needs a because/so chain.

IdentifyFrequency: 5

Name or point to the specific feature asked for — avoid extra explanation.

GiveFrequency: 11

Match the expected response style for “Give” questions.

ConvertFrequency: 3

Match the expected response style for “Convert” questions.

ConstructFrequency: 2

Match the expected response style for “Construct” questions.

WriteFrequency: 5

Match the expected response style for “Write” questions.

Time traps

Sections where candidates spent disproportionate time relative to marks

Paper 1: Section A …80m / 801 marks

Min per mark: 0.1

Syllabus traceability

Topics linked to questions and mark weighting in this session

Develop code

57 marks this session

Networks

13 marks this session

Algorithms

12 marks this session

Binary

10 marks this session

Emerging trends, issues and impact

8 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

LowHigh
Topic
2023
2024
2025
Σ

Develop code

57
57

Develop code (Programming)

37
37

Algorithms

12
11
23

Networks

13
10
23

Algorithms (Problem solving)

17
17

Constructs (Programming)

13
13

Emerging trends, issues and impact (The bigger picture)

12
12

Binary

10
10

Difficulty trend

How session difficulty has shifted across recent years

202320242025
2023 2023 · 3.8/52024 2024 · 3.5/52025 June 2025 · 3.0/5

Paper comparison

Marks and duration breakdown across papers in this session

Paper 1: Principles of Computer Science:

80 marks120 min

Paper 2: Application of Computational Thinking:

80 marks180 min

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

Self-diagnostic checklist

Key actions before you sit this paper — copy and tick off as you revise

  • 1Message

    The Summer 2023 Pearson Edexcel International GCSE Computer Science examination provided a balanced yet challenging test of candidates' skills across both papers.

  • 2Message

    Paper 1 (Principles of Computer Science) evaluated core academic and theoretical elements, while Paper 2 (Application of Computational Thinking) put practical coding and debugging proficiency under the microscope.

  • 3Message

    Feedback from the Principal Examiner reveals a widening gap between students who possess superficial knowledge and those who can apply computer science concepts in concrete contexts.

Teacher briefing pack

One-page session summary for tutors and classroom review

2023 2023

Computer Science

The Summer 2023 Pearson Edexcel International GCSE Computer Science examination provided a balanced yet challenging test of candidates' skills across both papers. Paper 1 (Principles of Computer Science) evaluated core academic and theoretical elements, while Paper 2 (Application

  • The Summer 2023 Pearson Edexcel International GCSE Computer Science examination provided a balanced yet challenging test of candidates' skills across both papers.

  • Paper 1 (Principles of Computer Science) evaluated core academic and theoretical elements, while Paper 2 (Application of Computational Thinking) put practical coding and debugging proficiency under the microscope.

  • Feedback from the Principal Examiner reveals a widening gap between students who possess superficial knowledge and those who can apply computer science concepts in concrete contexts.

Total marks
160
Duration
300 min
Session difficulty
3.8 / 5

Session analysis

The Summer 2023 Pearson Edexcel International GCSE Computer Science examination provided a balanced yet challenging test of candidates' skills across both papers. Paper 1 (Principles of Computer Science) evaluated core academic and theoretical elements, while Paper 2 (Application of Computational Thinking) put practical coding and debugging proficiency under the microscope. Feedback from the Principal Examiner reveals a widening gap between students who possess superficial knowledge and those who can apply computer science concepts in concrete contexts.

Updated Jun 13, 2026

Paper breakdown

Paper 1: Principles of Computer Science:

80 marks120 min

Paper 2: Application of Computational Thinking:

80 marks180 min

Top chapters

Develop code57 marks
Networks13 marks
Algorithms12 marks
Binary10 marks
Emerging trends, issues and impact8 marks

Exam structure insights

Marks by chapter

See where the marks were concentrated so revision time goes to the highest-value topics.

Networks13 marks
Network security5 marks
Encryption7 marks
Develop code57 marks
Emerging trends, issues and imp8 marks
Binary10 marks
Data representation4 marks
Data storage and compression6 marks

Mark accessibility

Estimate which marks were basic, mid-level, or high-difficulty.

75% within easy or medium reach

55
65
40
Easy: 55 marksMedium: 65 marksHard: 40 marks

Command word frequency

Spot common command words so answers match the expected response style.

State7 times
Describe10 times
Explain4 times
Identify5 times
Give11 times
Convert3 times
Construct2 times
Write5 times

Question type mix

Compare the mark share of each paper section and question type.

160Marks
  • Short Answer

    64·32·40%

  • Practical Coding / Debugging

    62·7·39%

  • Structured Description/Explanation

    22·11·14%

  • Multiple Choice

    6·6·4%

  • Extended Discussion

    6·1·4%

Study ROI

Bigger bubbles recur more often; higher bubbles carry more marks, helping you rank revision priorities.

DifficultyRecurrence %Develop codeBinaryNetworksAlgorithmsLogicEncryption

Time vs marks

Compare marks with suggested time allocation to plan exam pacing.

MarksMinutesMarks / min

Paper 1: Section A …

10.01 m/min
801
80

Total marks

801

Total time

80 min

Avg pace

10.01

Next-year prediction

Topics worth watching next year, with the reason shown directly below each bar.

TCP/IP Protocol Suite Layers

85%

85%

Data Storage and Compression (Huffman Coding)

82%

82%

Quick Sort or Insertion Sort Execution

80%

80%

Validation Rules (Range and Format Checks in Code)

78%

78%

Paper analysis

The Summer 2023 Pearson Edexcel International GCSE Computer Science examination provided a balanced yet challenging test of candidates' skills across both papers. Paper 1 (Principles of Computer Science) evaluated core academic and theoretical elements, while Paper 2 (Application of Computational Thinking) put practical coding and debugging proficiency under the microscope. Feedback from the Principal Examiner reveals a widening gap between students who possess superficial knowledge and those who can apply computer science concepts in concrete contexts.

Exam tips

Paper format

Duration
3h
Total marks
80

Analysis is paraphrased for study purposes. Always verify against the official examiner report and mark scheme.

COMPUTER-SCIENCE/21 — Pearson Edexcel IGCSE Computer Science (2023) | Revui