The value of computer-based product representations in co-designing with older users

Computer-based representations of products offer potential time and cost savings in the early design stages of new product development. As technology progresses they offer considerable scope for co-designing, giving users a voice early in the design process. However, few studies address how users relate to such models. A laboratory-based study was conducted with 13 older users (six men and seven women) to investigate their understanding of model formats used at an early stage of prototyping (i.e. on-screen digital images and physical rapid prototyped (RP) models). The results indicate that users were able to identify the basic purpose or function of a familiar product from the 2D line drawings. However, perceptions of size, weight and materials were poor, particularly with a less familiar product. Essentially, finished RP models and 3D colour computer-aided design images were found to communicate products more completely to users and therefore useful for eliciting feedback. Unfinished models were found to be confusing to users, but elicited more frequent suggestions for improvements indicating a role in co-designing. Guidelines are put forward to encourage optimum use of these models and to facilitate communication between users and designers.