Many consumer decisions are based on evaluation processes within families with many persons involved. Up to today, this multi-person character of most decisions concerning durables has not been taken into consideration adequately. In addition to that real decisions on durables are mostly multi-stage decisions. For both aspects a new measurement methodology is presented and applied to a sample of households. Every individual's influence on the different stages of family decision is quantified as regards the products cars, dish washers, and video-recorders. The findings reveal a comparatively high percentage of syncretic decision processes and offer insights in the family decision process which are important for media-planning as well as media copy decisions.