Practicing universal design to actual hand tool design process

• The context and concept of UD which evolves with time.
• Appropriate UD evaluation scales are varied on product attributes.
• User evaluation results are converted into product design factors.
• Examination of the importance of design factors by design verification.
• The proposal of new UD principles.

UD evaluation principles are difficult to implement in product design. This study proposes a methodology for implementing UD in the design process through user participation. The original UD principles and user experience are used to develop the evaluation items. Difference of product types was considered. Factor analysis and Quantification theory type I were used to eliminate considered inappropriate evaluation items and to examine the relationship between evaluation items and product design factors. Product design specifications were established for verification. The results showed that converting user evaluation into crucial design verification factors by the generalized evaluation scale based on product attributes as well as the design factors applications in product design can improve users' UD evaluation. The design process of this study is expected to contribute to user-centered UD application.