A Descriptive/Prescriptive Model for Menu-based Interaction

Abstract

As software systems continue to increase in sophistication and complexity, so do the interface requirements that support user interaction. To select the proper blend of ingredients that constitutes an adequate user interface, it is essential that the system designer have a firm understanding of the interaction process, i.e, how the selected dialogue format interacts with the user and with the underlying task software. One major approach to understanding the software design process and improving the quality of a product is through the use of models. The application of models to user/system interaction can provide the crucial feedback and innovative insights for designing and developing exemplary interactive systems. In this paper, we present one such model that describes as well as prescribes the critical elements for menu-based interaction and their interface dependencies. The model structure provides the flexibility for characterizing menu-based interactions that vary in levels of sophistication, and include 1) computational and decision capabilities based on task oriented actions, 2) user response reversal for error recovery, and 3) user directed movement. Finally, to illustrate the intrinsic power of our model, we present a <q>descriptive</q> narrative of two prominent menu-driven systems, Smalltalk and Zog, followed by a discussion of the model's <q>prescriptive</q> influence on the design and development of a third menu-based system, Omni.