The study of computing technology and user interfaces was initiated during the 1970s when industrial research laboratories began to focus on human-computer interaction (HCI) (Badre, 2002). In the 1980s, the personal computer was introduced, thus expanding the need for designing effective user interfaces. HCI became a discipline during this time, and the Association for Computing Machinery (ACM) established the Special Interest Group in Computer Human Interaction. One of the first textbooks on HCI, Designing the User Interface: Strategies for Effective Human-Computer Interaction (Schneiderman, 19891), was published. Shortly thereafter, HCI became part of the ACM curriculum promoting the development of effective user interfaces. Software tools were developed in order to assist in designing usable interfaces while employing usability engineering methods. Many of these methods focused on usability from the perspective of ease of use, ease of learning, user satisfaction, and zero defects (Nielsen, 1993).