Graphics to Report Evaluation Data") Purposefully Explain

¶ … Graphics to Report Evaluation Data") purposefully explain that data derived from various graphic styles can and should "tell a story" and provide a great deal more, including putting "a human fact on a project" (Minter, et al.). The graphics that the authors present include: bar chart, line graph, pie chart, illustrations including diagrams, maps and drawings, and photographs.

The main ideas that are to be taken into consideration when presenting data through graphics: a) keep it "simple"; b) you want to pick a graphic that "communicates the most important message"; and c) never presume that others will read the text that you prepare as an accompaniment to a graphic (Minter).

Before preparing bar charts, the authors suggest taking a very close look at an existing chart to determine what it shows, what conclusions can be drawn from it, and does it contain enough information? The title used above bar charts should use "precise language" so when readers go into the specifics of the chart, they already know what they will be looking for.

When readers are looking at pie charts, they are seeing proportions of the whole, but unless the chart is accompanied with supporting data, the reader could be misled. For example on page 335 the pie chart breaks down restaurants in Ozaukee County, explaining the percentages of venues that have smoking permitted in designated areas (39%); smoking not allowed at all (44%); smoking in any location in the restaurant (11%); and smoking allowed only at certain times of the day and only in certain areas (6%).

The problem though, as the authors point out, is that in this pie chart, the reader doesn't know whether all the restaurants in Ozaukee County were surveyed, or whether all were sent survey questionnaires and only some responded.

And while the authors warned earlier in this article to avoid a lot of extraneous information below the chart, in this case they suggest including "sampling methods, response rates, and limitations of results." When it comes to line graphs, they can illustrate the way trends differ (increase, decrease, or remain stagnant) over time. When the person creating the line graph uses "quantitative and qualitative data" correctly, it can present a "powerful story" for the reader.

Using illustrations can be a very effective way to pass along a wealth of information in a very small space, the authors explain. Moreover, illustrations have the potential to convey "technical information and geographic references" (Minter). In the illustration presented by the authors, reader can see that the illustration tells a "compelling story" about how the tobacco industry manages to be visible in an child's daily life, which is frightening.

Seeing the proximity of tobacco retailers -- juxtaposed with the closeness of the high school and middle school -- is poignantly clear thanks to this very simple, straightforward illustration. Photographs have always been able to convey information far better than the written word ("…every picture tells a story). It's a matter of getting a photo before and after the information has been presented, for the most powerful comparison. The checklist -- followed by numerous examples of how.