A decade of computer-algebra-aided online assessment of mathematics at the UK Open University

We reflect on over ten years’ experience of using the STACK computer-algebra-aided online assessment system to support the learning of large numbers of distance learning students at the UK Open University. The motivation for the use of, in particular, computer-algebra-aided assessment is discussed together with the use of formative practice quizzes to enhance learning and summative tests for assessment. We consider the challenges faced in the adoption and use of the system, as well as the successes achieved.