Product designers like the story of how James Dyson had 5127 failed prototypes before getting the cyclone vacuum cleaner right.
When product designers are learning to be product designers, they’ll spend a long time learning and investigating the properties of various materials. How polycarbonate takes a curve; what sort of shapes can be rotomolded; when to use stainless steel. Designers know that using a particular material requires a deep understanding of the properties of that material.
It’s accepted in design practices worldwide that producing a design requires prototypes. As the design moves from a sketch to a rough form to the first version through the production system more than a few trials and mockups are expected. Indeed, I’d say that if you suggested to a practicing designer that they could go straight from sketch to final production version they’d think you were a dilettante.
Yet, I hear from my students, and I see in their work, that they do not hold the same view about people’s interaction. That is, while they know to take care with the physical materials that make up a piece of work, they do not seem to take the same care when designing the interaction someone will have with their product.
The treat interaction as given, rather than something that can be shaped and guided. I’m firmly in the “you can’t design interaction, only design for interaction” camp. Just as you can’t design polycarbonate (materials engineers excepted), you can’t design the actions someone will take with your product. But you can design with those actions and work with them as you would any other material.