Charles Kostelnick is a professor of English at Iowa State University. He specializes in the area of visual rhetoric and communications. In his paper The Visual Rhetoric of Data Displays: The Conundrum of Clarity discusses in depth the connection between data displays and rhetoric.

It would almost seem a stretch to connect rhetoric with data graphs and displays, yet the two share a number of common elements. Like persuasive oration, a data display must in some way convince its audience of thinking a certain way. A graph cannot be a smattered mess of bars, crooked lines and circles, it must be organized and digestible, not unlike an orator choosing and organizing his words with great care. Similarly, if an orator comes off as dull and uninteresting, the audience will lose interest and any possibility of persuasion will be gone. With graphs, if not presented in an appealing fashion, the reader could simply overlook it and disregard its information. Finally, like we learn in science classes in school, the data on a graph must be displayed accurately, yet in such proportions to itself that the data stands out and one point does not get confused as another. An orator, too, must be objective and honest about his knowledge, yet be sure to emphasize certain points to more effectively get his point across.

The process by which we as humans understand and interpret data displays and oration differ. Like Kostelnick suggests, we understand data displays only because we have been taught how to read them, or by nurture. We understand oration, however, from the point in which we understand words, or by nature. Data displays are not built into us intrinsically, so we must learn how to interpret bars and numbers and points on a plane. While words are taught by nurture, to persuade an individual with them, however, is as much part of us as our own bodies.