Unexpected Complexity in a Traditional Usability Study
http://www.usabilityprofessionals.org/upa_publications/jus/2008august/howard1.html
  peer-reviewed

Howard, Tharon W.
Journal of Usability Studies
2008

Abstract:

This article is a case study of a demonstration project intended to prove the value of usability testing to a large textbook publishing house. In working with a new client, however, the research team discovered that what our client thought were simple problems for their users were actually complex problems that required the users to evaluate potential solutions in a surprisingly complex context of use. As Redish (2007) predicted, traditional ease of use measures were "not sufficient" indicators and failed to reveal the complex nature of the tasks. Users reported high levels of satisfaction with products being tested and believed they had successfully completed tasks which they judged as easy to complete when, in fact, they unknowingly suffered failure rates as high as 100%. The study recommends that usability specialists expand our definition of traditional usability measures so that measures include external assessment by content experts of the completeness and correctness of users' performance. The study also found that it is strategically indispensable for new clients to comprehend the upper end of complexity in their products because doing so creates a new space for product innovation. In this case, improving our clients' understanding of complexity enabled them to perceive and to take advantage of a new market niche that had been unrealized for decades.