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

Official 2026-2028 spec

These are the exact learning objectives Cambridge sets for this topic. Match the command word (Describe, Explain, State, etc.) in your answer to score full marks.

  1. Understand Understand the program development life cycle including analysis, design, coding and testing
  2. Understand Understand that every computer system is made up of sub-systems, which are made up of further sub-systems
  3. Understand Understand how a problem can be decomposed into its component parts including inputs, processes, outputs, storage
  4. Use Use different methods to design and construct a solution to a problem including structure diagrams, flowcharts, pseudocode
  5. Explain Explain the purpose of a given algorithm including stating the purpose and describing the processes involved
  6. Understand Understand standard methods of solution including linear search, bubble sort, totalling, counting, finding maximum, minimum and average values
  7. Understand Understand the need for validation checks including range check, length check, type check, presence check, format check, check digit
  8. Understand Understand the need for verification checks including visual check and double entry check
  9. Suggest Suggest and apply suitable test data including normal, abnormal, extreme, boundary
  10. Complete Complete a trace table to document a dry-run of an algorithm
  11. Identify Identify errors in given algorithms and suggest ways of correcting these errors
  12. Write Write and amend algorithms for given problems or scenarios, using pseudocode, program code and flowcharts
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).

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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.

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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