The last technique I will discuss will probably not seem like much of a technique at all: the humble table. Sometimes charts and fancy graphs are overkill. Tables are typically a better choice when
- The size of the data set is thin—less than a dozen data points, and spanning a single series.
- The data set contains many distinct series, no one of which dominates.
- The data are imprecise—designed to provide relative measures rather than precise, empirical absolutes.
- The idea conveyed in the exhibit cannot be explained by numbers alone, and depends on additional, textual exposition.
For example, financial report exhibits typically contain many data series. Each line item (for example, EBITDA) is a series unto itself. The audience might want to first look at EBITDA, then glance upward at the revenue line, and then back down to the GSA expense line. None of these series dominates, and each one needs some explanatory text (the left column) in order to be understood. Therefore, a table is a natural choice for this type of exhibit.
Evaluation matrices are also a classic table application. Figure 6-23 is an example of an exhibit that shows two data series: degree of trust and data sensitivity. Both are on a 1-to-3 scale. Neither set requires particular precision. Note the use of focused use of saturated blue and thin horizontal rules; they make the data "pop" while allowing the reader's eye to sweep sideways for context.
Figure 6-23 Sample Table
As with other types of exhibits, tables should be relatively free of ornament. In the example in Figure 6-23, created in a presentation package (PowerPoint), all the vertical table lines and margins have been erased. This is in contrast with the default PowerPoint layout, which puts solid black lines around each cell and a 2.25-point black line around the perimeter.
Sometimes decoration has its uses, however. Consider the famous Consumer Reports circular icons used in product ratings: black circles for "poor," lightly stroked white circles for "average," and red bull's-eyes for "excellent." In addition to being universally understood (always a good thing), the Consumer Reports icons retain their meaning even when reproduced in black and white. This is a subtle but often overlooked property worth emphasizing. Figure 6-24 shows an example done in a similar style, which packs quite a bit of information into a relatively small space.
Figure 6-24 Sample Decorative Table
This exhibit works well for a number of reasons. First, the icons are much easier to read than a sea of numbers, which are not easily distinguished. In addition, the saturated colored circles make the relatively "good" ratings really stand out, which in this case is what we want. Notice the subdued gray grid in the background and the thicker line separating the totals rows from the main table body. Imagine what this would have looked like if it had been done using default settings—that is, with a heavy grid, and with numbers instead of icons. Sometimes, it pays to spend a little extra time redrawing the table.