7.1

Algorithm design

Cambridge IGCSE Computer Science (0478)  · Unit 7: Algorithm design and problem solving  · 9 flashcards

Algorithm design is topic 7.1 in the Cambridge IGCSE Computer Science (0478) syllabus , positioned in Unit 7 — Algorithm design and problem solving , alongside Searching and sorting and Testing and validation.  In one line: An algorithm is a step-by-step procedure or set of instructions for solving a problem. Its importance lies in providing a clear and structured approach to problem-solving, enabling efficient program creation and execution.

This topic is examined in Paper 1 (computer systems theory) and Paper 2 (algorithms, programming and logic).

The deck below contains 9 flashcards — 8 definitions and 1 key concept — covering the precise wording mark schemes reward.  Use the 8 definition cards to lock down command-word answers (define, state), then move on to the concept and application cards to handle explain, describe and compare questions.

Key definition

The term 'algorithm' and explain its importance in computer science

An algorithm is a step-by-step procedure or set of instructions for solving a problem. Its importance lies in providing a clear and structured approach to problem-solving, enabling efficient program creation and execution.

What the Cambridge 0478 syllabus says

2026-2028 syllabus, in our words

What the syllabus expects you to be able to do in this topic, in plain English. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks. For the exact wording, see the official syllabus (PDF).

  1. Understand Understand each stage of a program development life cycle: analysis, design, coding, then testing.
  2. Understand Understand that any computer system consists of smaller sub-systems, and that each of these can be broken into further sub-systems.
  3. Understand Understand how to break a problem down (decompose it) into its parts: inputs, outputs, processes and storage.
  4. Use Use structure diagrams, flowcharts and pseudocode to design and build solutions to problems.
  5. Explain Explain what a given algorithm is for: state its purpose and describe the processes it carries out.
  6. Understand Understand these standard ways of solving problems: totalling, counting, linear search, bubble sort, and finding the average, maximum and minimum values.
  7. Understand Understand why input data needs validation checks, and know the different types: presence, range, length, type and format checks, plus check digits.
  8. Understand Understand why input data needs verification checks, and know the different types: double entry check and visual check.
  9. Suggest Suggest appropriate test data of four kinds (normal, abnormal, extreme, boundary) and apply it.
  10. Complete Complete a trace table that records what happens when an algorithm is dry-run.
  11. Identify Identify the errors in a given algorithm and suggest how to correct them.
  12. Write Write algorithms, and amend existing ones, to solve a given problem or scenario using pseudocode, flowcharts and program code.
Definition Flip

Define the term 'algorithm' and explain its importance in computer science.

Answer Flip

An algorithm is a step-by-step procedure or set of instructions for solving a problem. Its importance lies in providing a clear and structured approach to problem-solving, enabling efficient program creation and execution.

Definition Flip

Explain the purpose of pseudocode in algorithm design and provide an example.

Answer Flip

Pseudocode is a human-readable, informal language used to describe an algorithm's logic without strict syntax.

Example: `IF score >= 50 THEN DISPLAY 'Pass' ELSE DISPLAY 'Fail' ENDIF`.
Definition Flip

Describe the role of a flowchart in representing an algorithm. Provide 2 flowchart symbols and their meanings.

Answer Flip

Flowcharts use diagrams with symbols to visually represent the flow of an algorithm.

Example: Rectangle (process) and Diamond (decision).
Definition Flip

Explain the purpose of a trace table in algorithm testing.

Answer Flip

A trace table is used to manually test an algorithm by tracking the values of variables as the algorithm executes step-by-step. It helps identify errors in logic or calculations.

Key Concept Flip

What is 'decomposition' in the context of algorithm design, and why is it beneficial?

Answer Flip

Decomposition is breaking down a complex problem into smaller, more manageable sub-problems. This makes the problem easier to understand, solve, and test.

Definition Flip

Define 'abstraction' as it relates to algorithm design and provide an example.

Answer Flip

Abstraction involves hiding complex implementation details and focusing on essential features or functionalities.

Example: Using a 'sort' function without knowing its internal sorting algorithm.
Definition Flip

Describe 'sequence' as a basic control structure in algorithm design. Give an example.

Answer Flip

Sequence refers to the execution of instructions in a linear, step-by-step order.

Example: 1. Input number, 2. Square the number, 3. Display the result.
Definition Flip

Explain 'selection' and provide an example of its implementation in pseudocode.

Answer Flip

Selection allows an algorithm to choose between different paths of execution based on a condition.

Example: `IF age >= 18 THEN DISPLAY 'Adult' ELSE DISPLAY 'Minor' ENDIF`.
Definition Flip

Define 'iteration' and explain its purpose within algorithms. Give an example.

Answer Flip

Iteration (or looping) is the repetition of a block of code until a condition is met.

Example: `FOR i = 1 TO 10: DISPLAY i ENDFOR` (prints numbers 1 to 10).

Review the material

Read revision notes with definitions, equations, and exam tips.

Read Notes
6.3 Artificial Intelligence 7.2 Searching and sorting

Key Questions: Algorithm design

Define the term 'algorithm' and explain its importance in computer science.

An algorithm is a step-by-step procedure or set of instructions for solving a problem. Its importance lies in providing a clear and structured approach to problem-solving, enabling efficient program creation and execution.

Explain the purpose of pseudocode in algorithm design and provide an example.

Pseudocode is a human-readable, informal language used to describe an algorithm's logic without strict syntax.

Example: `IF score >= 50 THEN DISPLAY 'Pass' ELSE DISPLAY 'Fail' ENDIF`.
Describe the role of a flowchart in representing an algorithm. Provide 2 flowchart symbols and their meanings.

Flowcharts use diagrams with symbols to visually represent the flow of an algorithm.

Example: Rectangle (process) and Diamond (decision).
Explain the purpose of a trace table in algorithm testing.

A trace table is used to manually test an algorithm by tracking the values of variables as the algorithm executes step-by-step. It helps identify errors in logic or calculations.

Define 'abstraction' as it relates to algorithm design and provide an example.

Abstraction involves hiding complex implementation details and focusing on essential features or functionalities.

Example: Using a 'sort' function without knowing its internal sorting algorithm.

More topics in Unit 7 — Algorithm design and problem solving

Algorithm design sits alongside these Computer Science decks in the same syllabus unit. Each uses the same spaced-repetition system, so progress in one informs the next.

7.2 Searching and sorting

10 flashcards
7.3 Testing and validation

9 flashcards

Cambridge syllabus keywords to use in your answers

These are the official Cambridge 0478 terms tagged to this section. Mark schemes credit responses that use the exact term — weave them into your answers verbatim rather than paraphrasing.

algorithm pseudocode flowchart trace table decomposition abstraction step-by-step sequence selection iteration

Key terms covered in this Algorithm design deck

Every term below is defined in the flashcards above. Use the list as a quick recall test before your exam — if you can't define one of these in your own words, flip back to that card.

The term 'algorithm' and explain its importance in computer science
Explain the purpose of pseudocode in algorithm design and provide an example
Describe the role of a flowchart in representing an algorithm. Provide 2 flowchart symbols and their meanings
Explain the purpose of a trace table in algorithm testing
'abstraction' as it relates to algorithm design and provide an example
Describe 'sequence' as a basic control structure in algorithm design. Give an example
Explain 'selection' and provide an example of its implementation in pseudocode
'iteration' and explain its purpose within algorithms. Give an example

How to study this Algorithm design deck

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