Affordance, conventions, and design

Reviewer: Raphael M. Malyankar

Norman expounds on conceptual models, constraints and conventions, affordance, perceived affordance, and the role each plays in designing interfaces. He points out that, in the graphical screen-based interfaces that are most common today, it is perceived affordances that are controlled by designers, who rarely control the physical affordances of the system. He further points out that the graphical representations that signal possible actions to a user are based on conventions instead of affordances. Norman's position is that a clear understanding of these concepts and the corresponding tactics that designers can use leads to better-designed interfaces. This article is difficult to categorize. It is neither a straw man in a controversy, nor a research report, nor a methodology description, nor quite a tutorial article, nor wholly a position statement—it is perhaps more a statement of principles than anything else. But it expresses ideas that are fundamental to human-computer interaction, and expresses them rather well. On the principle of “know thyself,” it is well worth the time an interface designer will spend on it.