GCSE Computer Science - A New Approach
It is clearly the right way to do this, but it has taken bravery to finally commit to the solution. Pearson Edexcel's new GCSE in Computer Science represents a milestone in assessment. It has required clear thinking and radical changes to bring it to fruition.
Our goal was simple - to allow students who take GCSE Computer Science to be assessed by doing programming using a computer. To match the assessment with the learning and to make it relevant to how the outside world views computer science.
The challenges are; exam security must be rigorous; the assessment needs to be accessible reliable and fair and centres will need the infrastructure to run the assessments.
Firstly, no internet connection is permitted or needed during the onscreen assessment. The centre sets up an exam profile for the student in advance of the examination. The computer is set up to provide the students with the tools required to do their programming. These are the same tools that the students have been taught with during the two (or three) year program of study. No printing is enabled or required, no networking is needed or required everything is locally Installed and safe and secure. The centres retain responsibility for the implementation of proper security and invigilation. Data files are released digitally to the centres the morning of the exam and centre staff place them in each candidate’s user area. We have at least three channels prepped and ready to go to ensure that this works smoothly. There are; secure download from our website, secure download via Edexcel Online and as a final resort the question paper deliver team are ready to secure file transfer on request.
The challenge of setting tasks for assessment that are fair and reliable led us to making the decision to adopt one programming language. This means exam questions can be ramped in challenge and can be compared series to series very effectively.
The choice of programming language was not taken lightly, there are pros and cons to every language and every programmer has strong feelings about the language that they prefer. We choose Python because it is free, it Is widely used, and it is easy to start working with. It has tons of resources and training available due to its adoption into the education community in the last few years. It is used in industry widely. No company owns or controls it.
Another advantage of using a single programming language meant we could escape the overbearing reliance on a formalised pseudocode that was being used to facilitate paper-based assessment. Pseudocode is now in the subject content but in a more sensible way and without the need to impose counter intuitive structure to what in its essence should be free form.
There are downsides, the purist computer science community are disparaging about the way Python is eager to please in terms of setting the data types of its variables, it lacks closing statements to finish loops, rather relying upon white space and indents. All true, but students can learn quickly and the impact of making quick progress is that students become engaged. They may pick up habits that they will need to address in later life, if they end up pursuing careers in the field of programming and they use more syntactically rigorous languages. However, if students pursue careers in programming then this GCSE will have been at least partly responsible for the career choice.
Some teachers will be resistant to Python, perhaps they are skilled in another language and don't want to learn a new one (I was exactly this teacher at one time) but in the interests of the students I relented and now enjoy the freedom and flexibility of Python. It took no time at all and it is really beneficial for an experienced programmer to learn a new language in parallel with their students.
The GCSE requires that every student is assessed using a computer in a single exam session (no window of time) and some schools will find this challenging. The JCQ guidelines for computer-based exams recommend large separation between screens that can make assessment in large numbers a challenge. However, judicious use of screen shades and desk dividers can mitigate this to a great extent. We have offered our help in discussing these challenges and we feel confident that the advantage of an onscreen assessment is motivation enough for the schools to contact us and find a way to make it work.