CAS Secondary: On screen assessment in GCSE Computer Science

If you were unable to join us for the 'On-Screen Assessment in GCSE Computer Science' thematic community meeting, don't worry! You can catch up on all the content and a recording of the session below.

Key Takeaways

1. The shift to on-screen assessment – The new approach aims to provide a predictable and structured experience for students.

2. Python as the standard language – The exam board adopted Python to streamline assessment and ensure consistency.

3. No surprises for students – The exam is designed to be transparent, with clear expectations and supporting documents like the Getting Started Guide and the Programming Language Subset (PLS).

4. Managing infrastructure challenges – Schools using cloud-based IDEs can work with the exam board to ensure secure delivery.

5. Practical implementation – Exams require planning, with IT support, an exams officer, and the computing teacher working together to set up a smooth experience.

A Closer Look at the Session

The session, led by Tim Brady, provided an in-depth look at the rationale behind on-screen assessment in GCSE Computer Science. The discussion covered the evolution of the assessment format, the motivation for adopting Python as the sole programming language, and how the new approach benefits both teachers and students.

A key theme throughout was the principle of 'no surprises.' From assessment structure to question formats, the aim is to ensure students are well-prepared and not caught off guard. The session also highlighted how Python’s Programming Language Subset (PLS) helps clarify exactly what students need to know, reducing ambiguity in expectations.

Attendees also explored the logistics of running the exam, from distributing the digital files on the day to ensuring students work within a secure environment. While most schools can use their standard classroom setup, those relying on cloud-based environments like Replit must put measures in place to disable AI and collaborative features. The exam board is open to working with schools on practical solutions.

The structure of Paper 2 was also dissected, showcasing how students will interact with provided code files, complete tasks, and submit their solutions. The progression of question difficulty, from simple coding tasks to more open-ended problem-solving, was designed to be accessible while challenging students appropriately.

Next Steps: Reflecting on Your Practice

As you prepare your students for this assessment style, consider the following:

• Are you providing enough exposure to working within a secure, exam-like coding environment?

• How are you familiarising students with the PLS and the types of problems they might encounter?

• Does your choice of IDE align with the exam requirements, and have you tested it in exam conditions?

• How can you use past papers and practice materials to help students feel confident before the exam?

Here are a few practical exercises to incorporate into your teaching:

• Mock assessments using past papers – Simulate the exam experience with provided Python files.

• Syntax searching with PLS – Encourage students to get comfortable using Control+F to navigate the PLS document.

• Problem-solving under timed conditions – Have students attempt short coding challenges with a focus on structured, readable code.

Further Resources

• CAS Thematic Communities
• CAS Conference 2025
• Previous session recordings and example exam materials - Mission Encodeable
• Event Recording
• Pearson Edexcel GCSE Computer Science