Diverse methods are available for evaluation of (medical) interventions. In each case one has to decide on a specific method. Our aim was to analyze typical problems involved in the measurement of change. Different methods are delineated, and their specific pros and cons are set out. Subsequently, empirically derived recommendations are outlined on which method should be employed for which problem and under which circumstances. A characteristic of rehab treatment is that as a rule a multitude of problems are addressed, and accordingly, treatment goals are heterogenic. Straightforward recommendations for one or the other method cannot be given.