Don Norman at IIT Design Research Conference 2010:
“You gotta be careful too, because there are a lot of these research methods, like the rapid prototyping, like the ideation, like the brainstorming methods, like the ethnography, and so on, there is actually no real evidence that it makes a difference. Apple computer is a good example. You think they do design research? No. When I was at Apple, we did a lot of design research [...] We did a lot. We worried about all these fundamental things. We did user studies. We went to people’s homes. [...] You know what Steve jobs did when he arrived? He fired all of us! And guess what resulted? Better products! Which have revolutionized the way we use machines. And he fired the usability groups as well.” – Don Norman at DRC 2010
It’s worth watching the whole video – but you can fast forward to 13m20s to see the part quoted.