Over 79,000 students have just finished their GCSE exams in Computer Science: 9% more than five years ago. The majority of those students sat two traditional exams on paper but students sitting the Edexcel Computer Science GCSE had an on screen practical python exam.

There’s more to Computer Science than purely programming, but the practical skills of designing, writing, testing and debugging code play a pivotal role alongside the theory of logic, data representation, networks, security and ethical impact of computing.

The way that a subject is assessed has a significant impact on the way that the course is taught, which then affects how students engage with the content covered.

One of the main reasons that I wanted students at my school to sit Edexcel’s python on-screen test alongside their theory paper exam was to prioritise curriculum time for practical problem solving with code to consolidate and support the theory rather than being a tag-along extra.

I know that many schools have been waiting to see how those who’ve been involved in Edexcel’s pioneering python programming paper have fared, so I wanted to share my thoughts in the hope that I can persuade more schools to consider making the switch.

The context

I teach in a non-selective state academy in York with three specialist computing teachers. This year we had three classes of Y11s with a total of 67 students. Any student can opt for Computer Science GCSE, with 5 hours per fortnight throughout Y10 and Y11.

The logistics

Edexcel have provided a free, fully resourced scheme of work with topics being categorised as either Computational Thinking (CT) or Principles of Computer Science (P). We teach CT and P strands in parallel so that students have one lesson of practical programming each week, one lesson of theory and one lesson per fortnight for assessment, reflection or exploration.

Before their final exams, students had two mock python assessments under exam conditions: one in Y10 and one in Y11. Restrictions limit how close students can be sat together for on-screen tests but we have enough computer rooms to allow all students to sit the exam at the same time, where all students login with restricted exam accounts (no internet access).

Students are given a digital and paper copy of a python reference guide and a folder with python files to use as a starting point for each question in their printed exam question booklet. They then have two hours to work through the questions. Whilst students are welcome to annotate and highlight their question paper, the only thing that is submitted at the end of the exam is a zipped folder with all of the students’ code: there’s no justification, explanation, analysis or discussion in paper 2: it’s all about code comprehension, debugging, sequencing instructions and solving problems with code.

The advantages

Just before attending an online “debrief the exam series” event with other Computing teachers, I asked my current Y10 students if they’d like to switch to another exam board where they’d sit two paper-based exams. They’d just sat a challenging mock exam so I wasn’t expecting the unanimous enthusiasm for remaining with Edexcel’s on-screen approach.

Whilst there’s some benefit to being able to write out algorithms on paper (some software job interviews require this) but being able to write actual code on a computer allows students to test their code and edit their own mistakes.

The structure of the tests has been designed to be as accessible as possible: the six questions start with simple code comprehension or code completion activities. They progress to debugging and re-ordering code before building up to complex challenges to stretch the most able, involving manipulating data using files, 2d lists and string formatting.

The disadvantages

Some schools may struggle with the logistics of running the on-screen tests, although it is possible to stagger start times if you agree a schedule with the exam board.

Uploading student work after their exam was not a pleasant experience, with the predictable and preventable system crashes leading to an anxious time for many exams officers. Hopefully these teething problems will be resolved before next year.

Python is the most popular programming language at GCSE but schools who buck that trend will not be able to enter students for the Edexcel course as all questions have to be answered using a subset of Python 3. Edexcel has it’s own quirky way of laying out python code which takes some getting used to, but it’s consistent and I can see the benefits and rationale behind the pascal/delphi-like convention of declaring constants and variables at the top of your code, despite that not being strictly necessary in python.

The decision

We won’t know until GCSE results day if the decision to run with Edexcel’s on-screen python test was the right one but I’d encourage any other school to look seriously at the differences and consider switching. I’d love to hear your thoughts and reflections – do let me know via the CAS discussion forum.