Usability is Everybody's Business
http://www.stc.org/ConfProceed/1993/PDFs/Pg342345.pdf

Corbin Nichols, Michelle, Judith R. Fisher, S. Dawn Achee, Julia C. Stovall, David J. Dixon and Jane Emans Jesser
STC Proceedings
1993

Abstract:

Different types of usability tests can be performed at different phases in the product development cycle for different reasons. Writers can plan and implement a usability test and then incorporate recommendations into their documentation, thereby improving its usability. You can improve the usability of your documentation by performing one or more types of usability tests, no matter the size of the product or the time frame involved.