Cognitive Modeling for Assisted Graphical Design

Human reasoning about spatial environments, sketching and drawing in design , or solving of spatial configuration tasks often involves utilizing external graphical representations such as sketches, maps, or diagrams as well as mental spatio-analogical representations (e.g. in a visuo-spatial format, such as employed and constructed in mental imagery). Processes involved in the reasoning include those that operate more or less exclusively within the realm of external representations (e.g. in diagrammatic reasoning systems), those that operate on mental representations (such as in mental image inspection), and those that involve both mental and external representations (e.g. when reading an information item from a map and then using it in mental reasoning). For the latter group of processes, two types of functions can be ideal-ized, doubling in number by assuming internal and external perspectives: (1a) The external representations are constructed during the reasoning task and serve as externalizations to the mental reasoning processes. As such, they constitute a sort of graphical notes. (1b) The external representations provide information input to the construction of mental representations and to mental reasoning processes. (2a) The mental representations are constructed during reasoning on an external representation and they serve as temporary abstractions in extent, level of detail, or quality from the external. (2b) Mental reasoning on these abstractions can lead to modifying the external representations. For most problems of practical relevance, however, processes of the four groups are closely intertwined. The prevailing assumption is that that external graphical representations created during such tasks are created to aid the functioning of memory and/or mental imagery. As for memory, graphical representations are seen as extensions to mental storage (e.g. cf. Larkin and Simon, 1987; Tversky, 1999), especially with concern to working memory. As for mental imagery, external graphical representations are often seen to be part of a reflexive dialogue in which mental constructions are external-ized, internalized again, externalized, etc., thus creating an " eternal loop "