Comparison of Diagrams in Producing and Understanding Hierarchies in Three Different Application Domains

We compare diagrammatic representations of hierarchically ordered information in three different well-known application domains: organizational structure, folder and file structure, and calculation order in arithmetic expressions. Although there exists a natural link between hierarchies and trees, the diagrams conventionally associated with these domains are the tree diagram, indentation, and nested parentheses, respectively. To investigate the effects of inherent natural correspondence and convention on the production and comprehension of hierarchies, an experiment was set up. The results show that participants prefer tree representations for visualizing hierarchical structure of organizations and folders, but don’t construct trees for visualizing arithmetic hierarchy. In comprehension, differences were observed between the three interfaces for both response accuracy and response time. Trees performed best on accuracy. Parentheses took most time to process. When used in their conventional domain nested parentheses performed best. For trees and indentation, the results are less clear.