Abstract
“The intellectual tasks” of presenting evidence, Edward Tufte writes in Beautiful Evidence, are “to understand and to reason about the materials at hand, and to appraise their quality, relevance, and integrity.” An estimated 25% of space in scientific publications is devoted to tables, graphs, diagrams, and images. In fact, that figure is probably low for anatomic pathology, a field that revolves around collecting, interpreting, and sharing physical evidence. This latter step needs to be conducted at the highest levels, both scientific and aesthetic, and yet sometimes we encounter information in lectures or publications that has not been presented in the best possible way.
Considering the highly visual nature of anatomic pathology, practitioners will benefit from this book. The author's previous works have been very well received. First was The Visual Display of Quantitative Information (1983). Considered a classic in the field, the second edition (2001) has been called the “Strunk and White of visual design.” Tufte's other books are oriented along similar lines: Envisioning Information (1990) and Visual Explanations: Images and Quantities, Evidence and Narrative (1997). This third book includes both new information and a review of a few perennial issues. Tufte's material on statistical analysis and display is also available through national workshops, which are well worth attending.
Tufte offers a number of high-minded critiques. “Making an evidence presentation,” he exhorts, “is a moral act as well as an intellectual activity. To maintain standards of quality, relevance, and integrity for evidence, consumers of presentations should insist that presenters be held intellectually and ethically responsible for what they show and tell. Thus, consuming a presentation is also an intellectual and a moral activity.” To be effective, the presenter must offer information in ways that excite, involve, and convince the audience. In turn, the audience needs to understand what the presenter is saying and to decide if the evidence is believable.
Clearly, the author sets high standards, but ones that are also quite achievable. Pathologists will agree that simplicity, efficiency, and credibility are attributes of high-quality displays. These qualities apply to lectures and publications, of course, but also to computer software or displays, should we find ourselves in the position of designing, reviewing, or purchasing them.
In all of our presentations, we need to ask if we are showing, or have been shown, sufficient information to make educated decisions about the subject matter. Authors must concern themselves with a number of specific questions: How are size and scale depicted? Is the composition of the display appropriate? Does the layout of a presentation offer maximal support to the findings? How about the graphics? Are they “data intense, design simple”? Can graphics be incorporated into the text? Or vice versa? Are line drawings necessary to aid in understanding photographs? Is color necessary? If so, has it been used effectively? What is the best font style or size? Because data may come from multiple sources and multiple levels, their display happens best when words, numbers, and diagrams or other images are shown in coordinated fashion. Tufte provides discussions, with examples, of all these issues.
Corruption in presentations, according to Tufte, takes many forms and can distract the viewer or, worse, hide critical information. It can be obvious or subtle, intentional or accidental, but remains for presenter and audience alike to discern. When the display of data takes precedence over its analysis, the result is what Tufte calls “chartjunk,” the gaudy and useless imagery that can clutter presentations. Some software packages include cartoons that, when overused, project an amateurish visage or imply a certain contempt for both evidence and audience. Other features of software can limit presentations as well. Hierarchies of bullet points, for example, suggest an ordering of the data that may be unintended. To present information in the best possible way may require software that is not designed primarily for presentations. If this cannot be achieved, the author writes, use a handout.
The images come from 14 centuries, 16 countries, and 3 planets, which should be enough to maintain the interest of any visually inclined worker. The book is well worth the cost, not just for the many models and detailed analyses, but for its broad perspective, gorgeous artwork, and, not incidentally, its reproduction of Peter Norvig's PowerPoint® parody of Lincoln's Gettysburg Address. Individuals with varying levels of experience in academics, statistics, or graphics will probably have differing opinions, but hopefully all will share Tufte's delight in “poking a finger into the eye of thought.”