Chapter 1 Cases

Chapter 12, Additional Case 3: Evaluating and Revising Graphics

Background

The National Highway Traffic Safety Administration (NHTSA), under the U.S. Department of Transportation, carries out safety programs focused on improving the safety performance of motor vehicles and motor-vehicle equipment. The NHTSA also conducts research on driver behavior, vehicle use, and highway safety. You work in the documentation group for the Research and Development (R&D) program at the NHTSA. The R&D program provides scientific evidence to support the NHTSA's safety initiatives. You help R&D scientists prepare documents reporting the results of research and crash investigations. Often, the scientists' first opportunity to present their findings is at various professional conferences. The scientists use spreadsheet programs to create the graphics they need for their presentations and conference papers.

Recently, some scientists have retired and been replaced by new hires. Your boss, Elsa Beardsley, has asked you to help some of the new scientists: "I want you to work with Dana Shapiro, Megan Hamilton, and Allison Yamamoto. They are preparing papers for the 20th International Technical Conference on the Enhanced Safety of Vehicles in Nagoya, Japan. Specifically, I'd like you to review their graphics.

You ask Elsa why she thinks they need help with their graphics. "They're all good researchers," she replies. "However, when they report their findings, they don't always choose the most appropriate kind of graphics. They also unnecessarily complicate their graphics by adding a bunch of chartjunk. The spreadsheet application gives them too many choices when it comes to selecting a type of graphic or modifying a graphic, but the program doesn't offer them any help in choosing the kind of chart that works best for different kinds of information and readers.

You and Dana Shapiro are good friends, so you decide to stop by her office first. Dana shows you three graphics (Documents 12.1, 12.2, and 12.3) that she is planning to use in her conference paper. She also shows you the spreadsheet data she used to create each graphic.

Dana tells you that the Conference on the Enhanced Safety of Vehicles brings together about 1,000 representatives from government agencies, industry, and safety-advocacy groups worldwide to discuss research findings and advanced technologies related to vehicle safety. Her paper reports on the development phase of the NHTSA's research program on improved frontal protection. Specifically, her research assesses the crash conditions that result in the highest number of injuries or fatalities to drivers with air bags.

"What are you trying to convey in each figure?" you ask.

"In this first figure," Dana explains, "I want to show the distribution of frontal crashes into three different crash modes. In the second figure, I'm showing how the presence of air bags affects drivers' risk of sustaining serious or fatal injuries in four body regions. I want to show that arm injuries are slightly more likely with air bags than without them, but that lower-extremity injuries—the type that often lead to lifelong disabilities—are lower with air bags. In the last figure, I just want to show the average number of moderate lower-extremity injuries occurring annually to front-seat occupants in air-bag-equipped vehicles in our data set. I want to communicate the scope of the problem. I want people to know that an average total of 17,669 lower-extremity injuries occur annually in frontal crashes involving air-bag-equipped vehicles.

"What type of injuries are 'tib.plat' and 'tib.shaft'?" you ask.

"They're both types of injuries to the tibia, the lower leg.

"Thanks. I'll take a look at these more closely and get back to you later this week.

You also brieﬂy visit with Megan Hamilton and Allison Yamamoto. You note that their graphics feature the same ﬂaws as Dana's graphics. You decide that brief guidelines for choosing graphics in a spreadsheet program would be useful to the new R&D scientists. Besides, the guidelines might save you from repeating the same information to several scientists

Your Assignment

Using the techniques explained in this chapter, create guidelines to help the R&D program scientists decide which type of chart or graph to create.
Revise Dana Shapiro's graphics. Write Dana a brief memo explaining your revisions.