In assessment it is usual for students to be presented with the same sets of questions, regardless of their individual ability. That is, the questions are not tailored to the students’ individual performance, understanding and ability, and thus may be either too easy or too difficult for the student. However, computerised-adaptive testing (CAT) systems, present questions of appropriate difficulty for the student based on their ability, allowing the student to progress at their own pace. This paper presents such a system for self-assessment purposes and the findings from its use by a cohort of computer science students at first year undergraduate level.