Here are some considerations when incorporating different media. Charts, Graphs, Maps Photography and illustrations are representational of an object, concept, or situation. A chart or graph is a visual expression of quantitative information.
Charts allow the learner to examine data in relation to something else by means of comparison.
Avoid chart clutter. It will detract from the content. Charts and graphs make abstract figures more understandable by providing visual cues to the values and relationships expressed in the numbers. Whenever you need to present any form of numerical data to an audience, you should consider using a chart. Understanding Presentation Graphics.