The Iceberg Analogy of Usability
http://www-106.ibm.com/developerworks/library/w-berry/

Berry, Dick
IBM
2001

Abstract:

Developers sometimes ask which aspects of look and feel contribute most to the overall usability of an application or Web site. They are typically surprised when I answer that the 'look and feel' aspects aren't the major contributors at all. Look and feel have been popular discussion topics for many years, and some developers have proposed various schemes purporting to allow an easy swap of one look and feel for another. They were perhaps compelled to this thinking to compensate for an inadequate understanding of their users. Around 1990, I became alarmed by the popularity of design architectures advocating paradigms like the User Interface Management Systems (UIMS) that enable a pluggable look and feel. Many of my colleagues and I felt that look and feel represented only the tip of the iceberg. We felt that the set of concepts users must learn and understand to use a product or Web site effectively is actually the most important factor.