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

The digital skills in this qualification

  1. Designing and interpreting algorithms with flowcharts and pseudocode

    Assessed: In the exam

    Learners create, interpret, correct and test algorithms for real-life problems using sequence, selection, iteration, subroutines and arrays, and perform standard search and sort algorithms. Flowchart symbols and a pseudocode convention are fixed in Appendix B.

    DCF: Problem-solving and modelling

    Getting pupils ready

    Year 7
    Pupils draw a flowchart for a daily routine using the start, decision and input/output symbols, then swap with a partner who follows it exactly to spot wrongly ordered steps.
    Year 8
    Pupils play an unplugged card sort to act out linear search and bubble sort, then write the bubble sort steps as a numbered algorithm with a loop.
    Year 9
    Pupils write pseudocode for a quiz marker using IF, a FOR loop and a counter, then trace it with a trace table before coding it.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 1, Section 1.4.1 Algorithms, page 17

    “methods of defining algorithms, including pseudocode and flowcharts.”
    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 understand the importance of the order of statements within algorithms.

    Progression step 4

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

    • I can identify the different parts of an algorithm to determine their purpose.

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

    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 independently create and design models, and explain how they represent real-world problems, e.g. selecting and correctly using an appropriate method for illustrating a problem, such as a flowchart or spreadsheet.

  2. Decomposing problems and using abstraction to plan modular solutions

    Assessed: In the exam

    Learners analyse a scenario's requirements, break it into modular parts and model only the relevant aspects of the real world before designing a program.

    DCF: Problem-solving and modelling, Sourcing, searching and planning digital content

    Getting pupils ready

    Year 7
    Pupils break a Scratch maze game into separate jobs (move the sprite, detect walls, keep score) on a planning sheet before building each part as its own script.
    Year 8
    Pupils use Scratch custom blocks to turn repeated drawing code into a reusable 'draw shape' block with a size input.
    Year 9
    Pupils are given a short written brief for a cinema booking system, list its requirements, and draw a structure diagram splitting it into named Python functions.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 2, Section 2.1.1 Investigation, page 23

    “use abstraction effectively to appropriately structure programs into modular parts with clear, well-documented interfaces”
    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 independently create and plan work before beginning a digital task.

    Progression step 4

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

    • I can identify the different parts of an algorithm to determine their purpose.

    • I can select and effectively use a variety of planning techniques.

    Progression step 5

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

    • I can independently create and design models, and explain how they represent real-world problems, e.g. selecting and correctly using an appropriate method for illustrating a problem, such as a flowchart or spreadsheet.

    • I can plan my digital work effectively and with increasing complexity.

  3. 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.

  4. Designing and building a graphical user interface

    Assessed: In the exam

    Learners design and document input and output facilities for an effective user interface, then create and modify Tkinter windows, frames, widgets and buttons, including authentication routines.

    DCF: Evaluating and improving digital content, Creating digital content

    Getting pupils ready

    Year 7
    Pupils sketch the screen for a Scratch game, labelling every button and message, and explain why each is placed where it is.
    Year 8
    Pupils design a login screen wireframe in PowerPoint, gather classmates' feedback using comments, and improve the layout.
    Year 9
    Pupils build a simple Python Tkinter window with a label, an entry box and a button that checks a password and shows a message.
    Show the specification wording and the DCF statements

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

    “create new and modify existing intuitive Graphical User Interfaces (GUI) using the Python 3 built in Tkinter libraries, including:”
    Progression step 3

    • I can explain reasons for layout and content of my own work and the work of others.

    • I can ensure my output is appropriate for specific purposes.

    Progression step 4

    • I can justify the reasons for choices and explain the advantages and disadvantages of the different digital outputs I create.

    • 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 justify reasoning to critical audiences in terms of layout and content of my digital work.

    • I can use a variety of software, tools and techniques to create a professional, individual or collaborative project outcome incorporating a range of multimedia components.

  5. 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.

  6. Representing data in binary and calculating file sizes and compression

    Assessed: In the exam

    Learners convert between denary, binary and hexadecimal, explain how text, images and sound are stored, calculate storage requirements from resolution, colour depth and sample rate, and compare lossy and lossless compression.

    DCF: Storing and sharing, Creating digital content

    Getting pupils ready

    Year 7
    Pupils colour an 8 by 8 pixel grid from a binary code sheet, then count how many bits the image needs.
    Year 8
    Pupils record the same sound in Audacity at two sample rates, compare the quality and file sizes, and explain the difference.
    Year 9
    Pupils save one photo as BMP, PNG and JPEG, compare the file sizes and quality, and calculate the compression ratio in Excel.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 1, Section 1.2.1 Data types, including representation, storage and compression, pages 13 to 14

    “how to calculate the storage requirements for graphics using different dimensions, bit depths and colour depths.”
    Progression step 3

    • I can manage files and folders locally or online, e.g. move files to a folder.

    • I can use a range of software to select, produce and edit a range of multimedia components for a purpose, such as:

      • text and images, e.g. format text (bold, underline, italics, highlight); insert and edit text boxes; columns; use refine tools (spellchecker, find and replace); word wrap; crop; alter size and shape; alter images; add effects; trim and split sound and video clips; transitions; onion skin
      • presentation, e.g. page orientation; animations; transitions; remove and alter images; use background; use action buttons to create hyperlink; embed objects.
    Progression step 4

    • I can use appropriate advanced file management techniques, e.g. version history, restore previous version, tagging, compression.

    Progression step 5

    • I can make informed choices about file types and understand compatibility issues, e.g. the difficulties of editing PDFs, differences between sound files.

  7. Using Boolean logic and truth tables

    Assessed: In the exam

    Learners use AND, OR, NOT and XOR in truth tables to solve problems, and use relational operators in conditions.

    DCF: Problem-solving and modelling

    Getting pupils ready

    Year 7
    Pupils use Scratch 'and', 'or' and 'not' blocks so a sprite only moves when two keys are pressed together, then fill in a two-input truth table.
    Year 8
    Pupils build an Excel sheet using IF with AND and OR to decide which pupils qualify for a school trip, and check it against a truth table.
    Year 9
    Pupils complete AND, OR, NOT and XOR truth tables, then write Python conditions that match each table and test every row.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 1, Section 1.6.1 Logical operators, page 19

    “the use of logical operators in truth tables to solve problems, 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.

    Progression step 4

    • I can identify the different parts of an algorithm to determine their purpose.

    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.

  8. Recognising cyber threats and protecting personal data

    Assessed: In the exam

    Learners know threats such as malware, phishing and other social engineering, brute force and data interception, and the purpose of protections such as passwords, multifactor authentication, backups, firewalls and encryption.

    DCF: Identity, image and reputation, Storing and sharing, Online behaviour and online bullying

    Getting pupils ready

    Year 7
    Pupils sort a set of real and fake emails into 'safe' and 'phishing' and highlight the clues that gave each fake away.
    Year 8
    Pupils test sample passwords against a strength checklist, then set up multifactor authentication on their school Microsoft 365 account.
    Year 9
    Pupils encrypt and decrypt messages with a Caesar cipher by hand, then discuss why brute force breaks it and why modern encryption does not.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 1, Section 1.3.2 Cybersecurity and personal privacy, pages 15 to 16

    “social engineering such as phishing, pretexting, baiting, quid pro quo and impersonation”
    Progression step 3

    • I can understand how to protect myself from online identity theft, e.g. identifying secure sites, phishing, scam websites.

    • I can identify the benefits and risks of giving personal information and device access to different software.

    Progression step 4

    • I can use strategies for guarding myself against identity theft and online scams that try to access my personal information.

    • I can show an awareness of simple encryption and its purpose, e.g. to send sensitive data more securely.

    • I can act appropriately online, keeping myself safe and behaving in a responsible manner.

    Progression step 5

    • I can continuously evaluate online behaviour, taking into consideration the consequences of actions; take action to minimise risk to safety and security; consider global and cultural perspectives and adapt behaviour accordingly.

    • I can explain the ethical issues of corporate encryption, e.g. building in a bypass system.

    • I can recognise the risks and the uses of data/services on personal devices, within the terms and conditions of a range of software and web services, and identify how organisations become data compliant when using multi-national products.

  9. Weighing the legal, ethical and environmental impact of technology

    Assessed: In the exam

    Learners are aware of issues around manufacturing and disposing of hardware, automated systems and AI, network privacy, and intellectual property in software development.

    DCF: Digital rights, licensing and ownership, Health and well-being

    Getting pupils ready

    Year 7
    Pupils remix a shared Scratch project, credit the original creator in the notes, and discuss why copying without credit is plagiarism.
    Year 8
    Pupils research where an old school laptop goes when it is thrown away and present the environmental impact on one PowerPoint slide.
    Year 9
    Pupils debate whether an AI-driven automated system, such as a self-checkout or driverless car, should be allowed, using legal and ethical arguments.
    Show the specification wording and the DCF statements

    Where it is in the specification: Unit 1, Section 1.8.1 Systems development life cycle, page 21, and Section 1.1.1 Components, pages 11 to 12

    “legal and ethical considerations relating to intellectual property in software development.”
    Progression step 3

    • I can understand that copying the work of others and presenting it as my own is plagiarism.

    • I can identify the wider positive and negative influences of technology, e.g. on my life, on society, on the environment.

    Progression step 4

    • I can understand copyright and can explain the legal and ethical dimensions of respecting creative work, e.g. exploring the ethical and legal ramifications of piracy and plagiarism and know that they are irresponsible and disrespectful, and I can apply my understanding of the rules and regulations to different scenarios.

    • I can act responsibly as creator and user of creative work, e.g. exploring decisions that creators make when exercising their creative rights and responsibilities, giving consideration to ethical, real-life issues.

    Progression step 5

    • I can understand the legal and ethical debates that surround using other people’s creative work; and I consider the points of view of the original creator, potential audiences, and the broader community when using materials belonging to others.

    • I can understand the legal responsibilities for disposal of technology and the environmental impact of doing so.

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.