Reducing the cognitive requirements of visual programming

The authors evaluate a new general-purpose visual programming system, PrologSpace. The system addresses classic issues of visual interfaces: layout, shape, colour, and iconography; and those of particular concern to visual programming: multiple views (visual abstractions), synchronised views, integration of visual and textual dimensions, visual debugging, cognitive dimensions, and the problems of scale. They describe the system and examine its cognitive dimensions. They argue that: (1) PrologSpace enhances Prolog programming, and (2) PrologSpace has better `viscosity´, `visibility´, and `secondary notation´ than two other notable general visual programming systems and without any significant loss of dimensionality in other respects