For Web sites to succeed, they must be user-centered. A user-centered focus throughout Web site development life cycles promotes Web site usability. This is accomplished through usability engineering carried out within the context of software engineering.
Several frameworks have been developed to describe the human decision making process. The most popular is Simon’s three-phase paradigm of intelligence, design, and choice (Simon, 1960). This paradigm seems to be the most general, implying virtually all other proposed frameworks, and the Simon paradigm appears to have best withstood empirical testing (Martinsons, Davison, & Tse, 1999). Such scrutiny, however, has suggested the expansion of the basic formulation to conclude with an implementation phase.
During the intelligence phase, the decision-maker observes reality, gains a fundamental understanding of existing problems or new opportunities, and acquires the general quantitative and qualitative information needed to address the problems or opportunities. In the design phase, the decision-maker develops a specific and precise model that can be used to systematically examine the discovered problem or opportunity. This model will consist of decision alternatives, uncontrollable events, criteria, and the symbolic or numerical relationships between these variables. Using the explicit models to logically evaluate the specified alternatives and to generate recommended actions constitute the ensuing choice phase. During the subsequent implementation phase, the decision maker ponders the analyses and recommendations, weighs the consequences, gains sufficient confidence in the decision, develops an implementation plan, secures needed financial, human, and material resources, and puts the plan into action.
A variety of individual information systems have been offered to support the decision-making phases and steps. Much can be learned about this support by examining the individual systems’ components, architectures, and operations.
Key Terms in this Chapter
Usability: The potential for user efficiency, effectiveness and satisfaction, or simply, user success and satisfaction, when interacting with technology.
Accessibility: A subdomain of usability; enables people with disabilities to experience success and satisfaction with software to a degree comparable to that experienced by people without disabilities.
Evaluation: The process of assessing user-interface (UI) software for its ability to support users’ success and satisfaction in meeting their goals; not simply a matter of asking what the user likes and dislikes, but a process of collecting and analyzing human performance data (e.g., accuracy, task-completion times) and ratings of user satisfaction with the “look and feel” of the user interface; results of evaluation inform development of recommendations to improve the UI design.
Mental Models: Users’ psychological representations of the components and behavior of, for example, processes, products, services, and relationships.
Life Cycles: Structured frameworks for software development activities.
Software Engineering: Application of a systematic, disciplined, quantifiable approach to the development, operation, and maintenance of software ( IEEE, 1990 , p. 70).