“Absolutely,” Kobe confirms. “We started with bubble diagrams for the store, just saying ‘let’s try this or look at that.’ We then went from sketches and drawings to small physical models. We were making a physical model each week of different things. And then we went to full-size models in a mock-up room.
Link: The untold story of how Apple built a retail empire on trial and error
via http://www.fastcompany.com