The Google model relies on rapid experimentation and data. The company constantly refines its search, advertising marketplace, e-mail and other services, depending on how people use its online offerings. It takes a bottom-up approach: customers are participants, essentially becoming partners in product design.

The Apple model is more edited, intuitive and top-down. When asked what market research went into the company’s elegant product designs, Steve Jobs had a standard answer: none. ”It’s not the consumers’ job to know what they want,” he would add.

The Google-Apple comparison, Mr. Kao says, highlights the ”archetypical tension in the creative process.”