What Makes an Effective Visualization?
While each visualization is a unique creation for a particular range of uses, there are several overarching themes that can help both in creating new visualizations and selecting from existing ones for use in teaching. These principles emerged from a recent On The Cutting Edge workshop on Teaching Geoscience with Visualizations.
- The same things that work well in designing a class or educational activity work well in designing or selecting a visualization.
In particular, it is important:
- to know what you are trying to accomplish with the visualization: what are you trying to teach? What do you want the students to learn?
- To ascertain what the students already know as this will determine what they see and learn from the visualization
- To obtain feedback on how the visualization is working: does it convey the intended information? Work in the desired way? Enable the desired learning?
- Students don't always see what faculty are seeing when viewing a visualization.
Just as in other aspects of learning, what students see and learn from a visualization is built on what they already know. Understanding what students know and see can be addressed on three levels:
- Cognitive: what do students focus on in a visualization?
- Educational: how does the visualization promote generation of new questions?
- Geoscience: how do students understand and interpret the processes that are represented?
- Simple is usually better.
The power of visualizations comes from their ability to clarify relationships rather than from reproducing exactly the natural world. Thus, a design which emphasizes the desired relationships or information is likely to be more successful than one that makes every effort to be realistic. Students can become confused when elements of a diagram closely resemble the actual entity they represent in the real world (Uttal et al., 2006).
- Context is important and is easily lost.
Effective visualizations maintain the contextual relationships between the different parts of the visualization and between the visualization and whatever it represents. For example, when a series of diagrams are used to explain a process, it is important to keep the student aware of how each step in the progression relates to the overall process.
- Guidance helps.
Visualizations present a large number of relationships at a single time. Visual or textual clues can focus attention on meaningful items or guide the learner through the visualization in a particular order.
- Visualizations are most effective if their organization reflects the mental organization that the student is creating.
For example, if students create a series of still images in their mind to represent a geologic process, a series of still images will be most effective in conveying information. Similarly, if students create a mental movie, an animation may be more effective. (Tversky et al., 2002 ).