By DENNIS KOKS [Johnny Holland] – After one hundred twenty-one pages of critically analyzing images [in Beautiful Evidence], [Edward] Tufte comes with a number of (fundamental) principles for analytical design which are derived from the principles of analytical thinking. He emphasizes that these principles apply broadly and are indifferent to language or culture or century or the technology of information display:
- Show comparisons, contrasts, differences.
- Show causality, mechanism, explanation, systematic structure.
- Show multivariate data; that is, show more than 1 or 2 variables.
- Completely integrate evidence; words, numbers, images, diagrams.
- Thoroughly describe the evidence. Provide a detailed title, indicate the authors and sponsors, document data sources, show complete measurement scales, point out relevant issues.
- Analytical presentations ultimately stand or fall depending on the quality, relevance, and integrity of their content.
He continues with some pitfalls which need to be avoided in order to apply these principles right. Important is that both cause and effect are shown because that’s how we can determine what happened, by comparing before and after. The most common pitfall is that people start ‘cherry-picking’ (making a selection of the content which only advances their point of view). Furthermore one should be careful that the conclusions drawn from the data aren’t overreaching and that meaningless content doesn’t replace the real evidence…
Tufte suddenly devotes an entire chapter to a full frontal attack on MS powerpoint in which he boldly states:
The PP slide format has the worst signal/noise ratio of any know method of communication on paper or computer screen.
The arguments he provides for his statements are solid. In twenty-eight pages he explains how powerpoint’s workflow forces people to create bad presentations. From the emphasis on bullet structures to providing the wrong layout for data visualizations.