The design and evaluation of multiple interfaces: A solution for complex software

Computer software has become increasingly complex as advances in technology permit substantially more functionality to be provided to the user, a phenomenon which has led some people to describe today's heavily featured software as “bloated”. Despite the prevalence of this trend, the impact of complexity on the user has received little attention in the research community. This dissertation describes research that addresses that problem.; Study One, a comprehensive study that looked at the experience of 53 users of Microsoft Word, showed that while many users would like to have unused functions “tucked away”, most users were uncomfortable with the complete removal of unused functions. These findings suggested personalization as a promising direction for design and led to our Pilot Study which evaluated a multiple-interfaces prototype for Microsoft Word, where one of the interfaces was personalized to the user's individual needs. Results from that informal Wizard-of-Oz evaluation with 4 participants encouraged refinement of our prototype.; Study Two, a field study that included 20 participants, tested the effects of different interface designs on users' satisfaction and their perceived ability to navigate, control, and learn the software. There were two conditions: Microsoft Word with adaptive menus, and our user-adaptable multiple-interfaces prototype. Results showed that participants felt that they were better able to both navigate through the menus and toolbars and to learn with our multiple interfaces prototype. There were also important differences in satisfaction and control with the new design.; This dissertation shows multiple interfaces to be a promising design solution to complex software. The novelty of our design is the combination of three design elements: (1) Multiple interfaces, one is personalized, one is the full set of functions, and switching between interfaces requires a single button click. (2) The personal interface is adaptable by the user with an easy-to-understand adaptation mechanism. (3) The personal interface begins small and, therefore, unless the user adds many functions, it will be a minimal interface relative to the full interface.; Important advances in the understanding of individual differences with respect to the perception of complex software and in the understanding of adaptive versus adaptable interfaces are made.