The Web, of course, offers designers and innovators an unprecedented and powerful mechanism to test their ideas. They can mock something up, throw it up online, and get immediate feedback from users. Better yet, they can mock up multiple designs and test them quickly. Then, they can repeat the process until they home in on the design that seems to be most popular.  The approach may be the ultimate experiment in crowd-sourcing — letting users collectively design products. But experts in design and innovation say the approach has limitations and downsides.  “Getting virtually real-time feedback from users is incredibly powerful,” said Debra Dunn, an associate professor at the Stanford Institute of Design. “But the feedback is not very rich in terms of the flavor, the texture and the nuance, which I think is a legitimate gripe among many designers.”  Adhering too rigidly to a design philosophy guided by “Web analytics,” Ms. Dunn said, “makes it very difficult to take bold leaps.”  And as much as it may sound jarring, the customer is not always right.  “Customers sometimes do not know what they want,” said John Seely Brown, the co-chairman of the Deloitte Center for Edge Innovation, a research and consulting organization based in Silicon Valley. “It can be dangerous to just listen to what users say they need.”  None of this means that input from users is unimportant. Indeed, Ms. Dunn, Mr. Brown and others say designers must find a multitude of ways to understand users’ needs at a deeper level.  “It is more from engaging with users, watching what they do, understanding their pain points, that you get big leaps in design,” Ms. Dunn said.  That approach informed a redesign at Cooliris, a start-up whose software offers a way to view pictures and videos on a three-dimensional virtual wall of thumbnail images. In the new version, which Ms. Dunn helped design, the company includes headlines and other text next to images.  “Even though it changes the visual impact, it is critical that people have access to that information as they are scanning the wall,” Ms. Dunn said. “Now that it is out there, we can do the kind of micro-testing that Google talks about. But the broad design decision was not made that way.”  It is hard to criticize the results of Google’s data-centric approach. The company is hugely successful. If a certain hue of blue causes users to click on ads at even a marginally higher rate, it can translate into millions of dollars flowing to the company’s bottom line.  What’s more, many of Google’s products are utilitarian. They are meant to help people complete tasks quickly — not to dazzle them the way, say, an iPhone dazzles users.  Even Mr. Bowman insists he never meant to slam Google. “Google’s approach works really well for Google,” he said.  BUT Mr. Bowman has found a place that better suits his sensibilities. He is now the creative director at Twitter, where he says he has a greater opportunity to shape the look and feel of the service. Already his team has unveiled a major design overhaul. On the margin of users’ pages they added a search box and a list of “trending topics,” subjects that are most popular with tweeters at a given time.  He has also found a new way to listen to customers: reading their tweets in reaction to the new design features.  “Using data is fundamental to what we do,” Mr. Bowman said. “But we take all that with a grain of salt. Anytime you make design changes, the most vocal people are the ones who dislike what you’ve done. We don’t just throw the numbers in a spreadsheet.”  A previous version of this article and a caption on an accompanying photo misstated the position of Douglas Bowman. He is the creative director at Twitter.  A version of this article appears in print on , on Page BU3 of the New York edition with the headline: Data, Not Design, Is King in the Age of Google. Order Reprints| Today's Paper|Subscribe
Google, a company driven by engineering, expects design decisions to be backed up by data on customer preference. Is this shackling bold design?