Peter Merholz has written an interesting summary in the Adaptive Path Essays section which comments on better ways of finding users for research. He looks at a more scientific approach, by commenting that too much ?user research? is conducted, analyzed, and applied without anyone ever having spoken to users.
The relevance of User Research is important when gauging usability needs for a new or existing product, interface or design. A lot has been written about this, but as Peter comments, it is important to firstly find people who are likely to use the product, then interview enough of them so that trends emerge from their collective behavior.
Peter Merholz is a partner, along side Jeffrey Veen at Adaptive Path, a user experience company in the US and his personal web blog site, www.peterme.com contains a great archive and selection of posts and interesting comments on usability, information architecture and experience design.