How the exam works

Written 26 October 2026 from Pearson’s public documents. Always check the latest version on Pearson’s site.

The short version

• Two exams. Each one is worth half of your GCSE.
• Paper 1 is a written paper on Topics 1 to 5.
• Paper 2 is a programming exam on a computer, in Python, on Topic 6.
• There is no coursework. Your school signs a form to say you have had the chance to program in Python during the course, but nothing you write in lessons is marked.

Paper 1: Principles of Computer Science

There are five questions and you answer all of them. Each question is built around one topic, but the topics will not always come in the same order.

What it tests:

• Topic 1 Computational thinking. Decomposition and abstraction; reading and writing algorithms as flowcharts, pseudocode and code; trace tables; types of error; the standard searches and sorts (linear search, binary search, bubble sort, merge sort); judging how well an algorithm works; truth tables with up to three inputs.
• Topic 2 Data. Binary, two's complement, binary addition, logical and arithmetic shifts, overflow and hexadecimal; how text, images and sound are stored; units of storage, file size sums and compression.
• Topic 3 Computers. The CPU and the fetch-decode-execute cycle; memory, buses and secondary storage; embedded systems; operating systems and utility software; robust software; low-level and high-level languages; compilers and interpreters.
• Topic 4 Networks. LANs and WANs; how the internet is put together; wired and wireless; network speed sums; protocols and the TCP/IP model; topologies; network security.
• Topic 5 Issues and impact. Environmental impact; personal data; AI, machine learning and robotics; intellectual property; malware, attacks and protection.

Question styles you will meet: multiple choice, short answers, longer written answers, completing tables and working with diagrams.

Things to know:

• No calculator. Binary, file size and network speed questions expect you to work by hand or write an expression.
• Some questions target maths and some target computer-related maths.
• Pearson publishes a list of command words (for example "explain" and "discuss") in Appendix 1 of the specification. Learn what each one asks you to do.

Paper 2: Application of Computational Thinking

You sit at a computer with no internet access and write Python 3 in an IDE your school has set up. There are six questions and you answer all of them.

What you are given:

• coding files to start from, in a folder on your computer
• a printed question paper
• the Programming Language Subset (PLS), on paper and as a PDF on your computer.

What it tests (Topic 6):

• Developing code. Breaking a problem down; reading, finishing and improving code you are given; turning flowcharts and pseudocode into Python; writing code that is easy to read; finding and fixing syntax, logic and runtime errors; testing and judging a program.
• Constructs. Recognising the parts of a program; sequence, selection, count-controlled and condition-controlled loops and looping over data.
• Data types and structures. Integers, reals, Booleans and characters; strings, lists, two-dimensional lists and records; variables and constants; working with strings.
• Input and output. Responding to user input; reading and writing comma separated text files; validation; authentication.
• Operators. Arithmetic, comparison and Boolean operators.
• Subprograms. Using built-in and library subprograms; writing your own procedures and functions; local and global variables.

Things to know:

• The PLS lists everything Pearson will use when it sets Paper 2. If you know the whole PLS you can attempt every question. Correct code that goes beyond the PLS still gets marks.
• The PLS includes the random, math, time and turtle modules.
• Paper 2 is synoptic. It draws on ideas from the whole course, so Topic 1 skills matter here too.
• Learn your IDE before the day. The specification suggests line numbers, syntax highlighting, breakpoints, stepping and a variable inspector.
• Your work is saved into the folder your school sets up. Practise saving in the right place.

How marks are split by skill

Pearson marks three assessment objectives (AOs).

In plain terms: Paper 1 rewards knowing things and using them. Paper 2 rewards using what you know to solve problems in code.

Where to go next

• Work through the module checklist at the module checklist. Each row gets its own short video.
• Download the specification and PLS from Pearson (links below). We link to Pearson rather than host copies.

Sources

• Pearson Edexcel GCSE (9-1) Computer Science (1CP2) specification, Issue 1, January 2020 (qualification at a glance pages 4 and 5; subject content pages 7 to 14; assessment objectives page 18)
• Pearson assessment overview
• Pearson 1CP2/02 Programming Language Subset, Version 6, summer 2025
• Pearson 1CP2/02 Instructions for the Conduct of the Examination, summer 2026
• Qualification page

Pearson publishes the PLS for each summer by 31 January. Check for the summer 2027 version in early 2027 and update this page.