The great early designers such as the Eames, Gerstner and Sutnar were so good at what they did because they used the iterative process to create designs that put human functionality before form. They also wanted to design ways to bring quality at an affordable price. The Eames chair evolution was evidence of this. Using everything from plywood, to acrylic, to fiberglass then to leather. They should the evolution of the design, based on human needs. They also used new-at-the-time materials that the war popularized, like acrylic and fiberglass.
Dreyfuss’s methods of research included testing on every type of person, and designing for specific demographics. This differed from the previous ways of designers sitting in their offices, creating for ideal or imagined situations, not necessarily real-life scenarios.
