The Characteristics of an Effective Graphic

Printed Page 297-299

The Characteristics of an Effective Graphic

To be effective, graphics must be clear, understandable, and meaningfully related to the larger discussion. Follow these five principles:

Unnecessary 3D is one example of chartjunk, a term used by Tufte (1983) to describe the ornamentation that clutters up a graphic, distracting readers from the message.

The two-dimensional bar graph is clean and uncluttered; the three-dimensional graph is more difficult to understand because the additional dimension obscures the main data points. The number of uninsured emergency-room visits in February, for example, is very difficult to see in the three-dimensional graph.

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Figure 12.1 Chartjunk and Clear Art

ETHICS NOTE

CREATING HONEST GRAPHICS

Follow these six suggestions to ensure that you represent data honestly in your graphics.

  • If you did not create the graphic or generate the data, cite your source. If you want to publish a graphic that you did not create, obtain permission. Read more on citing graphics in How To Insert and Modify Graphics.
  • Include all relevant data. For example, if you have a data point that you cannot explain, do not change the scale to eliminate it.
  • Begin the axes in your graphs at zero—or mark them clearly—so that you represent quantities honestly.
  • Do not use a table to hide a data point that would be obvious in a graph.
  • Show items as they really are. Do not manipulate a photograph of a computer monitor to make the screen look bigger than it is, for example.
  • Do not use color or shading to misrepresent an item’s importance. A light-shaded bar in a bar graph, for example, appears larger and nearer than a dark-shaded bar of the same size.

Common problem areas are pointed out in the discussions of various kinds of graphics throughout this chapter.

Read more about white space, screens, boxes, and rules in Ch. 11, pp. 263 and 273. Read more about lists of illustrations in Ch. 18.

Integrating Graphics and Text

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It is not enough to add graphics to your text; you have to integrate the two.

  • Place the graphic in an appropriate location. If readers need the graphic in order to understand the discussion, put it directly after the relevant point in the discussion or as soon after it as possible. If the graphic merely supports or elaborates a point, include it as an appendix.
  • Introduce the graphic in the text. Whenever possible, refer to a graphic before it appears (ideally, on the same page). Refer to the graphic by number (such as “see Figure 7”). Do not refer to “the figure above” or “the figure below,” because the graphic might move during the production process. If the graphic is in an appendix, cross-reference it: “For complete details of the operating characteristics, see Appendix B, page 19.”
  • Explain the graphic in the text. State what you want readers to learn from it. Sometimes a simple paraphrase of the title is enough: “Figure 2 compares the costs of the three major types of coal gasification plants.” At other times, however, you might need to explain why the graphic is important or how to interpret it. If the graphic is intended to make a point, be explicit:

    As Figure 2 shows, a high-sulfur bituminous coal gasification plant is more expensive than either a low-sulfur bituminous or an anthracite plant, but more than half of its cost is for cleanup equipment. If these expenses could be eliminated, high-sulfur bituminous would be the least expensive of the three types of plants.

    In addition to text explanations, graphics are often accompanied by captions, ranging from a sentence to several paragraphs.

  • Make the graphic clearly visible. Distinguish the graphic from the surrounding text by adding white space around it, placing rules (lines) above and below it, putting a screen behind it, or enclosing it in a box.
  • Make the graphic accessible. If the document is more than a few pages long and contains more than four or five graphics, consider including a list of illustrations so that readers can find them easily.