Jeff Johnson is Principal Consultant at UI Wizards, Inc., a product usability consultancy (uiwizards.com). He also is a principal at WiserUsability.com, a consultancy focused on elder usability and accessibility. After earning B.A. and Ph.D. degrees from Yale and Stanford Universities, he worked as a UI designer and implementer, engineer manager, usability tester, and researcher at Cromemco, Xerox, US West, Hewlett-Packard Labs, and Sun Microsystems. He has taught at Stanford University, Mills College, and the University of Canterbury. He has authored many articles and chapters on Human-Computer Interaction, as well as the books GUI Bloopers, Web Bloopers, GUI Bloopers 2.0, and Designing with the Mind in Mind. His latest book, coauthored with Austin Henderson, is Conceptual Models: Core to Good Design (2011).