OCR GCSE Computer Science (J277)Specification point 2.1.2

OCR J277 2.1.2: Designing, creating and refining algorithms

The free BugBot lessons that teach this point, a robot to try it on, and the past-paper questions that test it.

What it covers

Before anyone writes a program, someone has to work out the steps. A set of steps that solves a problem is an algorithm. Algorithms are older than computers: a recipe is one, and so is the method you learned for long division. This module is about designing, describing, checking and comparing them, starting with what makes a good one.

• An algorithm is not a program
• Inputs, processes and outputs
• What makes a good algorithm
• Many algorithms, one problem

Or do it in the simulator, with tasks that mark themselves

Lessons that teach it

1. F5.1 What an algorithm is Algorithms
   Inputs, processes and outputs; what makes an algorithm precise; programs implement algorithms.
2. F5.2 Flowcharts Algorithms
   The standard symbols, and turning a flowchart into code.
3. F5.3 Pseudocode and the exam reference language Algorithms
   Reading and writing your board's pseudocode, and translating it into Python.
4. F5.4 Trace tables Algorithms
   Following an algorithm line by line, and tracing to find a logic error.

Try it on a robot

The task from F5.1 What an algorithm is, running here. Change the program and press Run.

Past paper questions on this

Real exam questions that test this, each worked through with a program you can run.

• AQA 8525 June 2025 Paper 1, Question 4: Validate a name by length until it is accepted, test data, and a username flowchart 13 marks
• AQA 8525 June 2023 Paper 1, Question 5: Trace a flowchart with a loop 3 marks
• AQA 8525 June 2022 Paper 1, Question 4: Which of two programs is more efficient, and why 3 marks
• AQA 8525 June 2022 Paper 1, Question 10: Trace a REPEAT UNTIL loop with DIV, then compare it with WHILE 8 marks
• AQA 8525 Sample Paper 1, Question 13: Move blocks between columns with MOVE and HEIGHT, keeping their order 10 marks
• OCR J277 June 2025 Paper 2, Question 2(a), (b): Count the passes of a flowchart loop, and describe the kinds of iteration 8 marks
• OCR J277 June 2025 Paper 2, Question 6(d): Trace a loop that totals an array, then refine it 7 marks
• OCR J277 June 2024 Paper 2, Question 2: Complete a flowchart that decides odd or even with MOD 4 marks
• OCR J277 June 2024 Paper 2, Question 9(b): Trace an if, elseif, else algorithm that scores a javelin throw 4 marks
• OCR J277 June 2023 Paper 2, Question 1(b) to (d): An assignment, the arithmetic operators, and a do until trace table 7 marks
• OCR J277 June 2022 Paper 2, Question 2(b): Design a flowchart that decides who gets a half-price meal 5 marks
• OCR J277 Sample Paper 2, Question 4: Usernames from a flowchart, then an algorithm for teachers and students 8 marks

The specification is OCR's own document; this page says which of our lessons teach point 2.1.2 and is not endorsed by the board.