Computer Based Assessment (CBA) is propounded as a technique which seeks to meet competing pressures within higher education, both economic and pedagogic. There is, however, a need to better understand the use of CBA across different subject areas and levels, identifying barriers and enablers to its efficacy whilst also ensuring its fit with other learning frameworks. This article considers, between two student cohorts, the impact of altering a CBA from a zero-staked formative to a low-stake summative instrument on a level one module for non-accounting specialists. The results show that whilst the student participation in the different elements of the module changed with a highly significant uptake of the assessment, there was a significant drop-off in seminar attendance, suggesting a substitutionary rather than a complementary learning resource. The performance of the students was not seen to change as a result of the revised assessment strategy. The results are discussed with suggestions made for further research. (Contains 6 tables and 5 figures.)