The Think Aloud Method and User Interface Design

Abstract

Daily use of computer systems often has been hampered by poorly designed user interfaces. Since the functionality of a computer system is made available through its user interface, its design has a huge influence on the usability of these systems (Carroll, 2002; Preece, 2002). From the user’s perspective, the user interface is the only visible and, hence, most important part of the computer system; thus, it receives high priority in designing computer systems. A plea for human-oriented design in which the potentials of computer systems are tuned to the intended user in the context of their utilization has been made (Rossen & Carroll, 2002). An analysis of the strategies that humans use in performing tasks that are to be computer-supported is a key issue in human-oriented design of user interfaces. Good interface design thus requires a deep understanding of how humans perform a task that finally will be computersupported. These insights then may be used to design a user interface that directly refers to their information processing activities. A variety of methodologies and techniques can be applied to analyze end users’ information processing activities in the context of a specific task environment among user-centered design methodologies. More specifically, cognitive engineering techniques are promoted to improve computer systems’ usability (Gerhardt-Powels, 1996; Stary & Peschl, 1998). Cognitive engineering as a field aims at understanding the fundamental principles behind human activities that are relevant in the context of designing a system that supports these activities (Stary & Peschl, 1998). The ultimate goal is to develop end versions of computer systems that support users of these systems to the maximum in performing tasks in such a way that the intended tasks can be accomplished with minimal cognitive effort. Empirical research has indeed shown that cognitively engineered interfaces are considered superior by users in terms of supporting task performance, workload, and satisfaction, compared to non-cognitively engineered interfaces (Gerhardt-Powels, 1996). Methods such as the think aloud method, verbal protocol analysis, or cognitive task analysis are used to analyze in detail the way in which humans perform tasks, mostly in interaction with a prototype computer system.