Abstract
To respond recent diversifying customer's needs of a product, one of the most vital work is to figure out customer's evaluation criterion of a product. Furthermore, emotional needs such as styling and user-friendliness, which is difficult to quantify, have been important factors with multitude of products having similar performance. Truly effective evaluation criteria often hide in customer's subconscious level, which is not easy to extract with frequency based statistics of conscious interviews, which is commonly used. In this paper, we propose an experimental method to externalize latent customer's evaluation criteria for product design. In this method, first, conscious perspectives for evaluating a product are extracted with evaluation grid method. Next, the extracted evaluation perspectives are mutually reviewed among the subjects and find effective latent evaluation criteria. We carried out an experiment based on the proposing method with a shape of pet bottle. With the experimental result, we show that there are more effective perspectives in the minority one than in the majority one and the effectiveness of unexpected perspectives extracted from another subject.