Heuristic User Interface Evaluation : Three Case Studies of Dialog Design

This paper discusses the use of heuristic guidelines in the design and evaluation of user interfaces. Closely following such recommendations can improve the user’s performance and reduce training costs. Three leading software applications are used as case studies in which the use of a simple set of heuristic guidelines has detected potential usability problems. Such problems can then be removed before more comprehensive usability evaluations are performed. INTRODUCTION The evaluation of user interfaces has traditionally held a low profile in software engineering. The application of such techniques has usually been either at the last stages of development or applied in a non-integrated fashion. This paper closely examines the dialog design of three leading software applications. The interfaces are summarised as they represent an excellent case study for the evaluation of user interfaces. Such real life examples provide concrete reference material for the application of Human-Computer Interaction (HCI) techniques in the software engineering lifecycle. Many have argued (Procter & Williams, 1992) that HCI should be owned by the software engineering community and that user interface concerns should be an integral part of the development cycle. Two of the major design aspects of user interfaces is consistency and feedback. Screen designs must look and behave consistently throughout the application and across similar applications. Appropriate feedback should also be provided for time consuming tasks and to indicate the status of options to the user. HEURISTIC GUIDELINES There is little question as to the benefits of user interface design guidelines and standards. Following user interface standards increases productivity for both the user and developer. Nielsen & Phillips (1993) outline the cost benefits of heuristic user interface evaluations and quote significant savings on increased expert user performance alone. Also, the costs of heuristic evaluations is lower than a formal usability evaluation. Other studies indicate that heuristic evaluations are a better method than cognitive walk-throughs for predicting specific problems (Desurvire et al, 1992). There are currently many thousands of usability guidelines available for developers. The guidelines cover a wide range of user interface areas and are available from a large number of sources. Guidelines are based on either heuristic knowledge or experimental evidence. The application of guidelines is usually a question of discovering the appropriate guidelines and extracting the relevant rules for the system being designed. Jeffries et al (1991) compared four usability techniques and report that heuristic evaluation identified the most serious problems with the least amount of effort. Nielsen (1992) also recommends that heuristic evaluations should be performed by a number of evaluators (three to five) to maximise results. However, Nielsen also states that usability specialists are more effective at finding problems, particularly specialists with expertise in the specific interface domain. There are three common classifications of guidelines: 1 International and national standards Heuristic User Interface Evaluation: Three Case Studies of Dialog Design