Decomposition and abstraction

Worked examples (9)

• 1Identify the inputs and outputs from a brief
• 2State what must be investigated when analysing a problem
• 3Choose a data type and justify it
• 4Explain why an identifier should be stored as text
• 5Extract a complete requirements list from a brief
• 6Separate requirements from design decisions
• 7Identify what a brief fails to specify
• 8Devise testable success criteria
• 9Produce a complete design from a brief

Model answers (9)

• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — extended open-response

Worked examples (9)

• 1Define decomposition for full marks
• 2Give two benefits with their consequences
• 3Decompose a straightforward problem
• 4Complete a structure chart
• 5Judge whether a decomposition is at the right level
• 6Distinguish decomposition from abstraction
• 7Decompose a larger system with two levels
• 8Explain why sub-problems should be independent
• 9Evaluate whether decomposition is always worthwhile

Model answers (9)

• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — extended open-response

Worked examples (9)

• 1Define abstraction for full marks
• 2Give an example of abstraction and say what was removed
• 3Distinguish abstraction from decomposition
• 4Decide what a system does not need to store
• 5Program an abstraction as a record
• 6Identify an abstraction inside a program
• 7Judge whether an abstraction suits a purpose
• 8Design two abstractions of one thing for different purposes
• 9Evaluate the claim that more detail is better

Model answers (9)

• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — short open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — open-response
• ✓Model answer — Edexcel 4CP0 Paper 1 style — extended open-response