Especially in our visually oriented society, no discussion of effective writing would be complete without a discussion of graphics. In addition to the kinds of illustrations discussed in this section, headings, typefaces, tables, and all the other elements of manuscript form can be considered graphic features.
Graphics have always been important, but computer technology has made it easy for writers to vary typefaces, to use boldface and italicized type, and to create tables and graphs. Graphic options, however, should always serve the audience and purpose of the paper. Most authorities seem to agree that the greatest danger in the new ease with which graphic effects can be created is the temptation to overdoto use too many typefaces, for example. A graphic element without purpose or meaning just makes the writer look foolish.
Although writers use many kinds of visuals, we will concentrate in this section on five: the pie chart, line graph, multiple bar graph, segmented bar graph, and combined line/bar graph. (See also photographs and the Research Paper.)
PIE CHARTS
Let's suppose you are doing a paper on aging in American society and want to show visually that the percentage of older Americans is increasing. If you are analyzing the increase year by year, the pie chart would be a good choice of graphic. In the pie chart, you present percentages as if they were slices of a pie. The entire pie equals 100% of the data (in this case, of the U.S. population). The slices indicate the percentage of Americans falling within the designated age brackets. You may use a different pie chart for each year you are analyzing. If it were
important for your reader to see these distinctions, it would be better to use a line graph or a bar graph. The pie chart loses its effectiveness if the differences among the slices are less than 5%. And if you have more than eight variables, the pie chart (or most other charts or graphs, for that matter) can become confusing. But if fewer than eight things are being compared and if the disparity between the sizes is relatively large, the pie chart can enhance your paper.
IN LINE GRAPHS
To show trends in your subject, you might choose to use a line graph. Line graphs allow readers to see increases and decreases over time. Because of their use in scientific documents, line graphs look more formal than pie charts, but they have the advantage of allowing the reader to distinguish numerical values more precisely.
MULTIPLE BAR GRAPHS
Multiple bar graphs can be effective if used wisely. Don't try to compare more than three variables; if you do, the bars become an indecipherable mountain range, and the reader becomes lost in the valleys and peaks. The multiple bar graph is effective if the variables on the horizontal axis are being examined individually (change within a single age bracket) as well as collectively (comparison of changes among age brackets). Because of its inherent visual appeal and the ease with which readers can distinguish between items, the multiple bar graph combines some of the best features of the pie chart and the line graph.
SEGMENTED BAR GRAPHS
Segmented bar graphs, like multiple bar graphs, allow readers to analyze variables found on the horizontal axis easily. However, the vertical axis sometimes causes problems. Notice that in the segmented bar graph the reader must calculate percentages for each age bracket after the foundation level of the year 1960. The difficulty in visually distinguishing percentages over the foundation level detracts from the effectiveness of segmented bar graphs. But these graphs can be visually appealing, and the reader can distinguish general trends with little difficulty.
COMBINED LINE/BAR GRAPHS
To help the reader overcome some of the problems in interpreting the segmented bar graph, you might choose to use a combined line/bar graph. The reader has the foundation of the first year, 1960, graphed as a bar, and all the other years are plotted above or below that foundation as lines showing increases and decreases. Some readers find the combined line/bar graph easier to read than a segmented bar graph.
OTHER GRAPHICS
You may wish to examine other types of visuals as you explore the best ways to enhance your readability. Photographs are useful in presenting exactly how your subject appears, and multiple photographs of the same subject help readers see differences in angles and in appearances over time (think of the photos, used to show weight loss, of the obese person eight months ago and the same person, slim and healthy looking, today). Pictographs, which show percentages with multiple pictures of the subject, can be interesting and effective.
