Using Diagrams to Design Information Systems

1 This paper is abridged and adapted from Nickerson, et al. in press. Specifically, only three of the problems presented to student designers are discussed here and an additive tree analysis of errors is added. Abstract Designers use sketches to offload memory and information processing and to promote discovery and inferences. Designers of information systems depend on topological connectivity rather than Euclidean distance. For such designers, understanding graph topology and manipulating graphs are essential skills, because graph manipulation facilitates the generation of alternative designs. We found that students of systems design have difficulties interpreting diagrams, revealing two biases: a sequential bias and a reading order bias. These biases lead to systematic errors of omission and commission while inferring connectivity from a diagram. The results have implications for teaching as well as diagram design.