The time course of information extraction from instructional diagrams.

This study investigated which information is extracted from a brief glance at an instructional diagram to assess its possible contribution for learning with text and diagrams. An experimental paradigm from scene perception research was used to study diagrams. University students (N = 20) saw pictures showing a scene or instructional diagrams for four different presentation times (50 msec. vs 250 msec. vs 1,000 msec. vs 3,000 msec.). Following presentation of a picture or diagram, respectively, participants were asked to verify a statement about its gist, details, and the functioning (for diagrams only). Repeated-measures analyses of variance (ANOVAs) were used to analyze verification accuracy for statements about gist, details, and the functioning as well as the eye movements (i.e., fixation durations and saccade amplitudes) during picture inspection. In both scenes and instructional diagrams, gist but not details were accurately identified from a first glance at the picture (i.e., at 50 msec. and 250 msec.). In contrast, verification accuracy for gist and details increased at a slower rate in instructional diagrams than in scene pictures over presentation times. Moreover, the characteristic function of increasing fixation durations with increasing inspection time was found in scenes, but not in instructional diagrams. Taken together, results suggest that both types of illustrations are processed differently at longer inspection times; however, patterns of early information extraction are similar, namely that the gist but far less information about details is extracted. Results imply people are able to extract an instructional diagram's global spatial structure from a first glance, which may be helpful to learning from text.