According to dual coding theory, learners possess both verbal and visual cognitive processes. Research has demonstrated that carefully developed visuals that incorporate verbal aspects can help improve comprehension since the information is stored both verbally & visually. As the learner develops a more concrete mental model based upon interrelated verbal and visual information, recall and application of prior knowledge will improve. Another advantage of visualization is that it can reduce cognitive load when engaging in higher order thinking such as problem solving. On the other hand, we must avoid including too many visuals or texts for fear of triggering excessive cognitive load, therefore impeding learning.
As educators who are using and/or creating online media to facilitate learning, we must consider a few things. First, the visualizations should include textual explanations and symbols to highlight important features and processes. Effectiveness is also enhanced when auditory narration accompanies the visual. Another consideration is the “streamlining of information.” For instance, is there extraneous information or imagery that does little to address the overall goal of the graphic? If so, this is an unnecessary addition to the learners cognitive load and should most likely be removed, even if it is aesthetically pleasing.
Below are two examples of visualizations that I have included in this year's flipped class screencast lectures with brief commentary on their perceived effectiveness. (See time ranges to cue to the location)
Example 1 (“Room for Improvement”)
Industrial Revolution Screencast (0:25 – 1:20)
Example 2 (Better Overall Design)
Auschwitz (10:00 – 13:00)
At about the 10 minute mark, I included this “professional” overview of the Auschwitz extermination camp. This brief clip includes many of the design principles characteristic of effective visualizations. For example, the European map includes the labeled camps, along with text of the audio narration along the bottom. There are also images of the camp included in the presentation as the narrator progresses. Additionally, animated symbols (arrows, diagrams, etc.) that accentuate points and show routes help learners comprehend historical processes and change over time. One critique is that since there are so many components of the visualization occurring simultaneously, lower skill learners may experience cognitive load issues. Since it is an online video, however, those students could always pause and/or review the material if necessary.
Of course, designing web-based visuals for the flipped class (or in education in general) is still in its relative infancy, so there is considerable room for improvement. It is nevertheless exciting that ditigal technologies have enabled educators and instructional designers to created visualization to improve student learning in new and innovate ways.