Backed by research
Some useful review material of usability research has just been published.

On the Web, Bob Bailey's Do's and Don'ts list is fully referenced to relevant research in the area, useful for anyone seeking to answer those “I'm looking for research that supports...” questions.

In print, meanwhile, the latest issue of the UPA's User Experience magazine carries an interesting ROI analysis for usable design, courtesy of Aaron Marcus. "Return on Investment for Usable UI Design" includes a summary table of quotes referencing usability statistics for a range of value propositions. Of particular interest is a four-page spread entitled "Proof for Usability's ROI Statistics and Examples", an extensive set of referenced quotes to a wide range of studies addressing issues such as trust, ease of learning, litigation deterrence and much more. The marterial draws fairly heavily on Bias & Mayhew's 1994 volume Cost Justifying Usability, but there are plenty of other references too. It's good to have so much ammunition in one place. According to the magazine, there's a plan to put this material on the UPA website, but there's no sign of it there yet.