| User interfaces for computer-aided design and other complex interactive computer graphic systems have progressed from text-based user-computer dialogs, to menu-based systems, and more recently, to icon-based systems. Interactive techniques are developed with the common goal of placing the user in control of computing processes during execution time. The user effectively becomes a part of the program, as the user makes key decisions while the program is running. A wide range of relationships are possible within this framework, but not all are equally compatible with the deisgn process. The least desirable interaction style is where the computer tells the designer what to do. A more common, but still problematic, interaction style is the "computer-as-apprentice," where the designer tells the computer what to do. Arguably the style most complementary to the design process, is one in which the designer becomes entirely unaware of the computer, attending only to his work. This is a familiar style for designers, who have long accomplished complex tasks with drawing tools and instruments. In the hands of the experienced designer, the tools required virtually no attention, and certainly no dialog. This thesis presents an interface based on the metaphor of tools, which encourages this style of work. A prototype of the interface has been developed that provides a set of simple tools. These simple tools may be connected into assemblages, according to a set of grammatical rules, to perform more complex tasks. This style of interface is named, scTIGRIS, for Tool-structured Interface and Graphical Interaction System. |
