Modeling a Graph Viewer’s Effort in Recognizing Messages Conveyed by Grouped Bar Charts

Information graphics (bar charts, line graphs, etc.) in popular media generally have a high-level message that they are intended to convey. These messages are seldom repeated in the document’s text yet contribute to understanding the overall document. The relative perceptual effort required to recognize a particular message is a communicative signal that serves as a clue about whether that message is the one intended by the graph designer. This paper presents a model of relative effort by a viewer for recognizing different messages from grouped bar charts. The model is implemented within the ACT-R cognitive framework and has been validated by human subjects experiments. We also present a statistical analysis of the contribution of effort in recognizing the intended message of a grouped bar chart.