Abstract
In recent years, designing products with which consumers or users are never satiated become more significant for designers and makers. The purpose of this work is to show factors of the satiety of Product design for Design evaluation. In the first half of this paper, after document investigation, it is found that satiety in products was almost the same process to change fromlike to dislike as satiety in foods. Thus we have proposed the hypothesis of satiety as follows: (1) Contact opportunity and Monotony, (2) Psychological satisfaction and Psychological dissatisfaction, (3) Plus identification and Minus identification. The hypothesis thatsatiety in products takes place in the process to shift from the former to the latter has been examined and considered by both questionnaires and the interview survey using portable audio products in order to confirm it. As a result, not only the hypothesis was muchverified by both research and survey but also other factors not defined in it were found. It is also found that the change of such value as life styles and so on has a power to prompt the shift from like to dislike and some memories or new meanings added in the product have another power to keep the shift back or delay it Through the case study of mini disk products, the cause relationship between satietyand cognitive parts (form elements) has been analyzed and studied by use of Rough sets and Quantification 1 of Multivariate Statistical Analysis in the latter half. That cause relation in the product was considerably and concretely cleared by the methods.
