The Application of Analogue Input and Output to Computer Programs Used as Design Tools

It is widely recognised that many designers have difficulty getting decision-support from the technical information that is available in many fields of expertise. A possible remedy is to display the relevant calculated relationships in a human-computer interface comprising an animated graph, ie a graph which is continuously and smoothly updated as the user manipulates analogue controls.
The theoretical premise is that this smooth and intimate interaction supports the intuitive mental processes, allowing the user to create internal mental models appropriate to the intuitive thinking employed in the creation of design. Evaluation is thereby made into a tool of synthesis. The key issue was believed to be the removal of closure, (ie the existence of definite input and output phases in the dialogue) and its replacement by a continuous two-way flow of information.
A series of animated interfaces was built. Preliminary tests ina context closely related to a particular design activity showed strong user preference for this form of interaction. A context-free implementation was set up and experiments were conducted to characterise the effects of closure on subject behaviour. Clear differences in user behaviour were observed to correspond to the existence of closure or its absence. However none of the metrics adopted reflected this to any great degree of confidence in numerical terms.
It is concluded that the interface is clearly attractive to users, who feel better supported by it. The failure to achieve corresponding benefits in terms of the numeric results is ascribed to the degree of abstraction incorporated into the design of the experiment, which impoverished its representation of reality. The need to exercise care in any abstractions made in further work is discussed and the option of field testing is recommended for consideration.