Maier and Fadel pioneered Affordance-Based Design (ABD) based on Gibson's revolutionary theory of affordances and Norman's deployment of the concept in his book, “The Design of Everyday Things”. Gibson (1979) introduced the affordance concept into the discipline of Ecological Psychology to address the interactions between an object and an agent. The Ecological approach includes the direct perception of affordances for the user along with a consideration of the users’ biomechanics. However, as the concept of affordance was imported and utilized in different disciplines, including engineering design, some important aspects of Ecological theory were omitted.
This paper is an attempt to review the definitions and different utilizations of the affordance concept focusing on the design of usable products to identify the different views and the missing elements. After addressing the divergent viewpoints of affordances, we provide recommendations to improve the usability aspects in ABD by considering direct perception and ergonomics. We claim that a design (based on affordances) that fails to address both criteria may result in a product that is less usable.