The purpose of graphical presentation of data is to provide a quick and easy-to-read picture of information that clearly shows what otherwise takes a great deal of explanation. The impact of graphical data is typically more pointed and memorable than paragraphs of written information.
No matter the topic of the data presentation or the audience, graphs offer inviting and easily interpreted methods of explaining information. Even people who are intimidated by figures are usually able to look at a graph and determine the most important points in a short span of time.
For example, a person making a presentation regarding sales in various states across the country establishes the point of the presentation to the audience more quickly by using a color-coded map rather than merely stating the sales figures for each state. Observers quickly determine which states are ahead and which are behind in sales, and they know where emphasis needs to be placed. Alternatively, when making a presentation on sales by age groups using a pie chart that divides the pie into various ages, the audience quickly sees the results of sales by age. This means that the audience is more likely to retain that information than if the presenter simply reads the results aloud or puts it into writing.