while usability testing will sometimes settle these arguments, the main thing it usually ends up doing is revealing that the things they were arguing about weren’t all that important. People often test to decide which color drapes are best, only to learn that they forgot to put windows in the room. For instance, they might discover that it doesn’t make much difference whether you go with cascading menus or mega menus if nobody understands the value proposition of your site.1445 ↱
Don't Make Me Think, Revisited
A Common Sense Approach to Web Usability
Steve Krug