When working for the firm Smart Design, designing a floor-cleaning robot for a company called Neato Robotics, I studied research that had been conducted around the Roomba and knew that shaping the vacuum’s personality would be as important in building a positive relationship between product and owner as any other element. To do that, my team and I dissected typical service personalities, like the hotel maid you never see, the chatty bartender and the proper nanny. “Which of these should this vacuum be?” we wondered.