A PORTABLE COMMUNICATION TERMINAL FOR NOVICES AND ITS USER-INTERFACE SOFTWARE

Portable terminals have the potential of providing information and com munication services not only to computer experts at their offices but also to many users being in a variety of daily life situations. The cu rrent user interfaces (UIs) of portable terminals are not suitable for a novice user of computers; they require some knowledge on computers from a user. To overcome this problem, the authors tried to implement their knowledge on the daily life in the design of a UI for novice use rs. As a result, two UI mechanisms, called Novice Interface and Graphi cal Metaphor Interface, which provide operations, expressions, and dat a structures in a way similar to those usually used in daily life are proposed. Novice Interface is to provide easy to use environment. It a dopts a direct manipulation device with three buttons and a model of d ata structures, called Small World Model, that limits the number of fu nctions and the depth of hierarchical menu. Graphical Metaphor Interfa ce, being an extension of Novice Interface, is to provide services wit h a display screen that makes them well-understandable for any user. T he proposed UI mechanisms were implemented in a prototype terminal and its software platform. The former offers several applications of the information services (like teleshopping, home banking, or database ret rieval) and the communication services (like pen-based image mail, sof tware fax, or telewriting); the latter enables those application progr ams to provide a consistent UI.