The economics of interface development

This paper argues that decision theory can be used to identify diierent attitudes towardsùsability engineering'. The advocates of formal methods and ethnomethodology argue that initial investments ooer substantial beneets to subsequent development. For other groups, high cost techniques are seen to ooer few rewards for interface design. The following pages exploit utility curves to represent these diierent perspectives. The intention is not to map out all of the complex factors that aaect human decision making but to focus on the interaction between issues of cost and probability in commercial project management. Decision theory provides analytical techniques that can be applied to the resulting models. In particular, risk preference coeecients are used to explain part of the reluctance to exploitàdvanced' design techniques for human computer interfaces. Later sections exploit the utility curves to identify an agenda for future research in human computer interaction.