Object modeling for user-centered development and user interface design: the wisdom approach
Nuno Nunes · Portuguese National Funding Agency for Science, Research and Technology (RCAAP Project by FCT) · 2001
ion Presentation Control PAC Aplication Conceptual Interface (ACI) Instantiation of a User Interface System Functional core Output Input User User Functional core Figure II.23 Conceptual Architectural Models for User-interface Objects In the late 1980s and early 1990s several approaches of implementation architectural models for interactive systems emerged. Unlike conceptual models, implementation models organize the interactive system as a set of software components and aim at practical software engineering considerations like reusability, maintainability, and performance. The Seeheim model [Bass, 1992] proposes a simple three-layer model (application, dialogue and presentation) of an interactive system, roughly coupling the semantic, syntactic and lexical functionality’s of the user interface. The application component models the domain-specific components, the dialogue component defines the structure of the dialogue between the user and the application and, finally, the presentation component is responsible for the external to internal mapping of basic symbols. The Seeheim model is considered a correct and useful model for specification of interactive systems [Duce et al., 1991]. However, its support for distribution, concurrency, resource management and performance is recognized to be insufficient. Background: A Brief Survey of Usability Engineering and Object Modeling 58 The Arch model [Pfaff and Haguen, 1985] is a revision of the Seeheim model aimed at providing a framework for understanding of the engineering tradeoffs, specifically, in what concerns evaluating candidate run-time architectures. The Arch model proposes a five-layer approach balanced around the dialogue component. The components of the Arch model are: • The interaction toolkit component implements the physical interaction with the end-user; • The presentation component provides a set of toolkit independent objects; • The dialogue component is responsible for task-level sequencing, providing multiple view consistency, and mapping the between domain specific and user interface specific formalisms; • The domain adapter component implements domain related tasks required but not available in the domain specific component; • The domain specific component controls, manipulates and retrieves domain data and performs other domain related functions. Application Dialogue Presentation Seeheim Model