Prototypes have different forms. According to an article written by two apple computer employees, Houde and Hill (1997), prototypes prototype the “role” of a product, its “look and feel,” or its “implementation.” Therefore, designers should choose a right type of a prototype.

One step further, prototypes serve different roles. When I visited IDEO last summer, I found three boards which describe what prototypes do; they “inspire,” “experiment (evolve),” or “validate (specify)” a product. This suggests that different types of prototypes can serve different purposes for a product.

Given that there are different types of prototypes and different objectives of prototypes, designers should create different types of prototypes for different objectives. For instance, the “role” prototype can be more appropriate when designers inspire a product, while the “look and feel” prototype can be better when designers validate a product.