抄録
The purpose of this study is to investigate the structure of human preference for products and the relation among the attributes of preferred products. After asking many subjects about their each preferred automobiles as the case of products and the reason, the reducts of shape attributes of individual automobile and all the automobiles every subject prefer are calculated using rough set theory. Finally, it is clarified that all subjects have their proper plural way of preference in accordance with their own plural points of view, when the reducts of shape attributes of all automobiles any subject prefer are divided into groups for each automobile, those groups of reducts have a kind of family relation as a whole.
