This paper discusses the use of student performance data as an input to the last phase of a needs-assessment evaluation. The weaknesses for this purpose of national pupil norms are examined and it is suggested that improved data is required to reflect the many differences that exist between schools. Specifically, two changes are proposed: the provision of national school norms with standardized tests as well as pupil norms, and, if feasible, norms for different "types" of schools. Hypothetical examples are presented in graph form and the uses of such data are discussed. (AE)