Abstract representations such as graphs involve a complex syntax that must be learned before the representation is useful. Representations that are introduced with insufficient attention to student understanding only add complexity and result in confused learners. Coupling a familiar, direct experience with a more abstract representation of that experience is a helpful way of letting the student learn about the abstract representation.
The Rationale Behind the Feature (Specific Design Principle):
Learners need to be able to couple real (or simulated) situations with abstract representations of data from the situations. The two types of display should be simultaneous.
Context of Use:
Our realization of this principle came with probes and graphs, but applies to visualizations and simulations as well. In Biologica, students see drawings of dragons with different features while also looking at their genetic makeup. In Molecular Workbench, students see atoms and molecules bouncing around while also seeing the temperature calculated for the ensemble.
In our earliest work with probes in 1985 we discovered that it was critical that a graph be drawn at the same time that something was being measured. Heather Brassell, who was interested in Mary Budd Rowes wait time research, did a thesis that showed the importance of this in the context of the motion detector. She saw a marked decrease in learning if the display was delayed until the end of a run, typically 10-15 seconds. Jan Mokros and I found that late elementary grade kids with no knowledge of graphs could learn to interpret data from graphs that were drawn at the same time as they measured temperature. In other words, not only could kids coordinate the real thing with an abstract representation (the graph), they also quickly learned how to interpret the abstract representation. Much of the value seemed to come from the fact that the two were simultaneous.
In later software, we included a Slolam game which challenged kids to match a computer graph with a graph they would generate by moving in front of a motion detector. We could observe kids making a mistake in interpreting the representation (e.g. moving forward instead of backward) and then quickly correcting themselves because they could see instantly the error of their ways.
Brassell, H. (1987). The effect of real-time laboratory graphing on learning graphic representations of distance and velocity. Journal of Research in Science Teaching, 24(4), 385-395.
Mokros, J., & Tinker, R. (1987). The impact of microcomputer-based labs on children’s ability to interpret graphs. Journal of Research in Science Teaching, 24(4), 369-383.