Graphs as aids to knowledge construction: Signaling techniques for guidingthe process of graph comprehension

Graphical displays are frequently used to express quantitative information in texts, but viewers are sometimes unable to comprehend and learn the rele vant information. According to a cognitive analysis, graph interpretation i nvolves (a) relatively simple pattern perception and association processes in which viewers can associate graphic patterns to quantitative referents a nd (b) more complex and error-prone inferential processes in which viewers must mentally transform data. Experiment 1 establishes that graphs can be r edesigned to improve viewers' interpretations by minimizing the inferential processes and maximizing the pattern association processes required to int erpret relevant information. In Experiments 2 and 3, the researchers isolat ed one important factor that affects viewers' interpretation (i.e., the per ceptual organization of the information in graphs). If relevant quantitativ e information is perceptually grouped to form visual chunks (because releva nt data points are either connected in line graphs or close together in bar graphs), then viewers describe relevant trends. If relevant information is not perceptually grouped, viewers are less likely to comprehend relevant t rends.