Use-Cases and Personas: A Case Study in Light-Weight User Interaction Design for Small Development Projects

Introduction An information system is an arrangement of people, data, processes, interfaces, networks, and related technologies that interact to support the information needs of an organization (Whitten, Bentley, & Dittman, 2000). Organizations devote large amounts of effort and resources to developing these information systems. Once they are developed, it becomes crucial both to the success of the information system and the success of the organization that users use the information system appropriately and effectively. Yet users of information systems often find those systems unusable. One review of software research found that the average software program has forty design flaws that impair employees' ability to use it, costing up to 720% in lost productivity (Kreitzberg, 1996). The discipline of systems analysis and design benefits from many established tools and techniques, including Project Evaluation and Review Technique (PERT) for project management, Entity Relationship Diagrams (ERD) for data design, Data Flow Diagrams (DFD) for process design, and Unified Modeling Language (UML) to name a few. One area that generally lacks formal tools and techniques is user interface design. Numerous approaches of user interface design have been proposed, so many that it is unlikely that "one size fits all. " This paper presents the results of a case study project to develop a small information system. For this small project two tools were used for the user interface design: use-cases and personas. This paper will review the literature on user interaction design leading to the selection of these two tools for this particular case study. The paper will discuss how these tools were applied in this development project. Finally, the paper will discuss the results. Literature Review In human-computer interaction the interface is what users see and work with to use a product (Hackos & Redish, 1998). However, the human and the computer do not share equal roles in the interface. The user is flexible and adaptable (Mayhew 1992), while the system is neither. One result of this inequity is that the responsibility for the interaction is placed on the user. Another result is that the design of the interface is an important issue in how users perceive the system. Barki and Hartwick (1994) concluded that user participation and involvement towards a system affect their productivity and attitude in the workplace. User communication with the system is expressed in two languages: the action language and presentation language (Gerlach & Kuo, 1991). The user communicates through actions to tell the computer what tasks or commands need to be done. The computer communicates through a presentation language to ask about the tasks and objects and to respond to requests with the result of the operations. Both of these languages allow interaction and communication about common tasks and domains. Foley and van Dam (1982) devised a four-level user interface model. The conceptual level describes the domain of tasks through which the user and the system interact, such as the objects that are to be manipulated and their relationships. The semantic level defines the meanings of words, incorporating objects that are part of the presentation language of the system, such as menus, dialog boxes, etc. The syntactic level describes the grammar that allows combining words into a meaningful context. This includes the appearance and disappearance of objects on the screen and also the order of actions done by the user. The fourth level is the lexical level, dealing with how the words are expressed. This includes font types, colors, lines, etc. Satzinger and Olfman (1998) demonstrated that interface consistency is an important element in user interface design, based on the Foley and van Dam model. Information presentation and display formats has an impact on user preferences and decisions (Tractinsky & Meyer, 1999). …