Normative values and neuropsychological assessment. Common problems in clinical practice and research

In this paper some methodological problems related to the use of normative data in neuropsychological assessment are analysed. The difference between the concepts of normality and mastery, and the problems encountered with the adjustment of raw scores for age and education are considered. Other arguments discussed and exemplified with real data are the use of inner and outer nonparametric tolerance limits, confidence limits for individual scores, multivariate norms, and discriminant analysis.