Introduction - Paper Prototyping: The Fast and Easy Way to Define and Refine User Interfaces - page 14

Usability for Everyone
For products to truly become usable, the development team can't rely on a handful of usability
specialists to gather and interpret data from users; this creates a bottleneck that either slows the
development process or forces usability activities to be skipped entirely (guess which). Thus, it's good
for product teams to have a way to collect at least some of this usability information for themselves.
You wouldn't discourage a friend from taking singing lessons simply because he isn't an operatic tenor
like Pavarotti. Similarly, I don't think it's necessary to be an HCI (human-computer interaction) guru to
get started with paper prototyping. Paper prototyping and usability testing are common-sense
techniques, and people in a variety of disciplines can benefit from using them. Yes, some will be better
at it than others, but like my parents always told me, "You never know until you try."
On the other hand, usability specialists can spend decades developing their knowledge and skills.
There is a great deal to know about the fields that comprise HCI, including cognitive psychology, social
psychology, statistics, experimental design, data analysis, interface design principles, and probably
others. I don't mean to summarily dismiss all that collective wisdom by implying that any idiot can
conduct a good usability study. My philosophy is simply that anyone who cares about making better
interfaces can benefit from learning the basics of paper prototyping and usability testing. But there is
always more to learn.