This paper describes the context and rationale for the introduction of computer-based assessment (CBA) on a first-year module in geographical data analysis, and evaluates student opinion and performance in response to this. Questionnaires showed that students were generally positive about CBA, and overall module evaluations improved. Student interest in the subject-matter also increased. Comparison of summative examination performance before and after the introduction of CBA showed an increase in average marks, with particular improvement shown in the range of marks 35-50 per cent. These results show that CBA can be effective in delivering improved student performance as well as being popular with students.