Prototyping for user feedback : how visual detail can influence feature preference

User-centered design focuses on insights drawn from users to drive product development. Provisional design prototypes are often used as a tool for collecting feedback from users that can then be incorporated into future design iterations. However, experience from design practice suggests that user feedback should not always be taken verbatim, and that the particular context in which a prototype is presented can greatly influence the user's perception of the concept. The theory of preference construction helps design researchers understand how users' preferences are dependent on the particular context of a design representation. Thus, it is important for designers to have insight into the potential effects of contextual factors. This thesis presents the results of a survey of -200 users for their responses to four prototype designs for a handheld GPS unit with exactly the same screen size but differences in two key visual details: a bezel surrounding the screen and an overmolded edge around the unit. Results showed that screen size was a key consideration in the respondents' perception of the product, but that the addition of a bezel seemed to reduce the likelihood that they would state a preference for a larger screen. These findings can be incorporated into guidelines to aid design practitioners in maximizing the value of the feedback they receive from users on provisional prototypes and sketches. Thesis Supervisor: Maria C. Yang Title: Associate Professor of Mechanical Engineering & Engineering Systems