So as it turns out, the art of graphing data goes deeper than many imagine. While the word “graph” may conjure images of bars of data for a middle school science experiment, their potency goes beyond proving that, say, atmospheric pressure affects boiling points of water. A graph tells a story and it is up to the designer of said graph to tell that story in such a manner than can persuade its recipient to believe in something.

To say the least, a simple pie chart is often not enough. Maybe that pie chart has too many elements for one circle. Or maybe the data becomes muddled and unclear. So maybe you try a bar graph only to find that it is equally confusing and banal. In the case of Ed, the intrepid “grapher” in question, a line graph proved to be the most efficient at conveying the message he wanted to get across. But just plugging numbers into Excel and having a line graph come out does not guarantee maximum efficiency and persuasiveness. So Ed must tinker with color, thickness of lines and where labels will go. Should there be a legend? Or should each line be labeled individually?

You might be wondering why any of this matters. Take a courtroom for example where an attorney’s job is to persuade the jury to think like he wants them to. Telling a story and appealing to the jury’s pathos is a good move, but pathos alone won’t win trials or even have them take place at all. Evidence must be introduced so that the ruling will have a factual basis. Graphs can play a role in determining innocence or lack thereof and can appeal to the jury’s logos and ethos. Logos is appealed to by the data. Numbers are facts and presenting them in a clean and easy to understand graph can mean all the difference. Should the jury find a graph confusing and not informative, it may as well have not been introduced at all. Ethos is appealed to here because a jury will be impressed and more likely to respect an attorney that has prepared such well-made graphs for a trial.

An online legal dictionary describes graphs and their role in demonstrative evidence in the courtroom as follows:

Graphs and charts are perhaps the most useful forms of demonstrative evidence. These tools can vividly illustrate a loss of earnings, a decrease in life expectancy, and past and future medical bills. Clear and concise charts can help a jury to arrange a complex set of events in a chronological fashion… Graphs and charts can be presented to a jury in a variety of ways. In addition to offering the standard large prepared poster board on an easel, some attorneys prefer to create charts as they speak to the jury, using large blank pieces of poster board and colored marker pens. Other attorneys like the dramatic effect of dimming the courtroom lights and using an overhead projector or computer screen to focus visual attention on their illuminated charts and graphs.