Graphs and charts work wonders to demonstrate your ideas, messages and insights to the audience of your presentation. They allow you to accurately display sets of data and represent trends in a meaningful and visual way.
I have found though that while accuracy is important it is almost more important to be clear with the insight of information you are trying to convey. So, when including graphs and charts in your presentation be sure to consider the following.
Every graph or chart should be focused on a single or main idea. However, the question you should ask yourself about the element is “what do I need to convince viewers of” and make sure that it is doing this.
For example, if you won’t the chart to represent a sales trend then that should be the only insight that could be derived from the graph.
Use emphasis and contrast to highlight the main idea. Colors, pointers, labels and markers can all be used to highlight the most important elements. In your graph, you can highlight the primary component in color and have the rest grey.
You can further isolate the main idea by grouping non-relevant sections together as another category or making them smaller or thinner. The key is to reduce the visibility of the non-target elements.
The main idea or insight can be further enhanced through the adoption of visual conventions. For example, it is almost universal that green is good, red is bad or north is up and south is down. Take advantage of these.
It is possible and still important to represent the other data in the graph or chart as it provides broader context. If you are demonstrating a single data point then show as few data points as possible, if it is a trend then show as many as you can.
Finally, data should only be presented together if a clear relationship exists. If unrelated data is presented side by side then it may result in your viewers believing a relationship exists when it doesn’t.
The key takeaway is to ensure that your graphs and charts are not just accurate but also clear. If a single data point or trend is not obvious then your audience may not pick up on it. Ideally, you should spoon-feed your audience the insights that you want them to take away.