The paper explores a range of issues relating to the design and use of computer-based test interpretation (CBTI) systems. It describes a number of dimensions along which CBTI systems vary and considers both the positive and negative implications of these for test users, for their clients and for test candidates. A distinction is drawn between systems that generate finished reports and those that generate questions or guidance for the user. The question of how the validity of narrative reports can be assessed is considered. A study on the discriminative validity of reports generated by the PREVUE ICES CBTI system is reported which shows clear differences between judgements made about true and bogus reports. It is concluded that there are two main issues to consider when evaluating a CBTI system: first, the validity of the information generated by it and, second, the ways in which that information is likely to be used.