DCF Cymru Digital competence for Wales

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GCSE Computer Science

Both units are sat on screen. Unit 1 tests theory (algorithms, data representation, networks, cybersecurity, logic, the systems development life cycle) and Unit 2 asks learners to design, write, test and refine Python 3 programs with a Tkinter interface in IDLE against a pre-released scenario. The single biggest thing KS3 should build is confident algorithm design and debugging: pupils who can decompose a problem, write it as a flowchart or pseudocode, then code, test and fix it arrive ready for Unit 2.

Awarding body
WJEC
Level
Level 1 and Level 2
First taught
September 2025
Amount of digital work
High
Specification
Open the specification
How this qualification is assessed
  • Unit 1: Understanding Computer Science: Digital examination 1 hour 30 minutes, 50%, 80 marks
  • Unit 2: Computer Programming: On-screen examination based on a pre-released brief, 2 hours, 50%, 80 marks, set and marked by WJEC

Skills that use Data and information literacy

  1. Writing Python programs that use data types, lists, records and file handling

    Assessed: In the exam

    Learners design, write and refine Python 3 code using variables, data types, selection, iteration, string handling, lists, dictionaries, subroutines and reading from and writing to files, with self-documenting identifiers and comments.

    DCF: Problem-solving and modelling, Data and information literacy

    Getting pupils ready

    Year 7
    Pupils build a Scratch quiz that stores the score in a variable and uses a repeat loop and IF blocks to check answers.
    Year 8
    Pupils move from Scratch to Python by writing a short text adventure that uses input, variables and IF, ELIF and ELSE.
    Year 9
    Pupils write a Python high score program that stores names and scores in a list, sorts them and saves them to a text file.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 2, Section 2.3.1 Implementation, page 25

    “use basic file handling, including:”
    Progression step 3

    • I can create and refine algorithms and flowcharts to solve problems, making use of features such as loops, Boolean values and formulae.

    • I can construct, refine and interrogate data sets within tables, charts, spreadsheets and databases to test or support an investigation.

    Progression step 4

    • I can create a simple model or self-contained algorithm.

    • I can identify repeating patterns within an algorithm and use iteration to make the algorithm more efficient.

    • I can create a data capture form, capture data, search data and create a database and spreadsheet with appropriate data input method.

    Progression step 5

    • I can demonstrate the benefits of compartmentalising sections of a problem (using functions/procedures).

    • I can develop logical solutions to determine the input, outputs and processes of a program, e.g. following pseudocode or a flowchart to come to an outcome, developing a written sequence of steps that could be followed.

  2. Testing and debugging with typical, extreme and erroneous data, and validating input

    Assessed: In the exam

    Learners design and carry out a test plan, present test outcomes with commentary, and create and modify validation and verification routines, refining code in response to testing or changed requirements.

    DCF: Problem-solving and modelling, Data and information literacy, Evaluating and improving digital content

    Getting pupils ready

    Year 7
    Pupils are given a Scratch program with three planted bugs, find and fix them, and record each fix in a simple table.
    Year 8
    Pupils add Excel data validation to an age entry column (whole numbers 11 to 16) and test it with a typical, a boundary and an invalid value.
    Year 9
    Pupils write a test plan for their Python high score program with typical, extreme and erroneous inputs, run it, and screenshot each result with a comment.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 2, Section 2.4.1 Testing, page 26

    “design test data to include examples of typical, extreme and erroneous content”
    Progression step 3

    • I can understand the importance of the order of statements within algorithms.

    • I can construct, refine and interrogate data sets within tables, charts, spreadsheets and databases to test or support an investigation.

    Progression step 4

    • I can detect and correct errors in algorithms.

    • I can create a data capture form, capture data, search data and create a database and spreadsheet with appropriate data input method.

    • I can suggest and make improvements that are relevant for audience and purpose, based on feedback and self-evaluation of my digital work.

    Progression step 5

    • I can develop logical solutions to determine the input, outputs and processes of a program, e.g. following pseudocode or a flowchart to come to an outcome, developing a written sequence of steps that could be followed.

    • I can make detailed and specific changes to my digital work, based upon feedback and self-evaluation, as relevant.

Good to know

Links with other qualifications

GCSE Digital Technology shares the binary data representation, compression calculation, cyber threats (phishing, social engineering, man-in-the-middle attacks), data validation and legal and ethical content, and its practical work also involves coding (JavaScript arrays, string methods and form validation), so Years 7 to 9 work on these skills serves both GCSEs; the binary, logic and storage calculations also draw on Mathematics number skills.

Source: WJEC GCSE Computer Science specification, teaching from 2025, for award from 2027, Version 3, September 2025.