Shah, P., Mayer, R.E., & Hegarty, M. (1999). Graphs as aids to knowledge construction: signaling techniques for guiding the process of graph comprehension. Journal of Educational Psychology, 91(4), 690-702

Shah, P.; Mayer, R.; Hegarty, M.

1999

Shah, P., Mayer, R.E., & Hegarty, M. (1999). Graphs as aids to knowledge construction: signaling techniques for guiding the process of graph comprehension. Journal of Educational Psychology, 91(4), 690-702

2

Graphical displays are frequently used to express quantitative information in texts, but viewers are sometimes unable to comprehend and learn the relevant information. According to a cognitive analysis, graph interpretation involves (a) relatively simple pattern perception and association processes in which viewers can associate graphic patterns to quantitative referents and (b) more complex and error-prone inferential processes in which viewers must mentally transform data. Experiment 1 establishes that graphs can be redesigned to improve viewers' interpretations by minimizing the inferential processes and maximizing the pattern association processes required to interpret relevant information. In Experiments 2 and 3, the researchers isolated one important factor that affects viewers' interpretation (i.e., the perceptual organization of the information in graphs). If relevant quantitative information is perceptually grouped to form visual chunks (because relevant 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 trends.

Experiment 2 demonstrates that both format and scale influenced the relative ease and difficulty of interpreting different quantitative information from a graphical display. Second, the task of the graph viewer may interact with the role of graph characteristics. Specifically, line graphs may be better when the task is to describe trends, whereas bar graphs may be better when the task is to describe facts.

40

8