Kansei engineering as a tool for the design of in-vehicle rubber keypads

Manufacturers are currently adopting a consumer-centered philosophy which poses the challenge of developing differentiating products in a context of constant innovation and competitiveness. To merge both function and experience in a product, it is necessary to understand customers' experience when interacting with interfaces. This paper describes the use of Kansei methodology as a tool to evaluate the subjective perception of rubber keypads. Participants evaluated eleven rubber keys with different values of force, stroke and snap ratio, according to seven Kansei words ranging from "pleasantness" to "clickiness". Evaluation data was collected using the semantic differential technique and compared with data from the physical properties of the keys. Kansei proved to be a robust method to evaluate the qualitative traits of products, and a new physical parameter for the tactile feel of "clickiness" is suggested, having obtained better results than the commonly used Snap Ratio. It was possible to establish very strong relations between Kansei words and all physical properties. This approach will result in guidance to the industry for the design of in-vehicle rubber keypads with user-centered concerns.