Beautiful Evidence is Edward R. Tufte’s fourth book on visual evidence. His earlier books about this topic where ‘Visual Explanations’, ‘Envisioning Information’ and the highly praised ‘The Visual Display of Quantitative Information’. Beautiful Evidence deals with analytical design and is a collection of critically analyzed (and very beautiful) images, principles and pitfalls which apply to everything from MS Powerpoint to sculptures.
Analyzing different visualization methods
The first four chapters respectively deal with mapped pictures, sparklines, links & causal arrows and words, numbers, images together. By critically analyzing beautiful images Tufte succeeds in explaining which characteristics make these methods work for a certain goal. Also for each method some principles are presented at the end of the chapter.
A great example of this is the analyses of Alfred Barr’s book cover / table of contents / history map for the Cubism and Abstract Art exhibition in 1936, pictured here below on the left (on the right is Tufte’s stripped down version which he uses to explain the role the arrows play within this visualization).
Art-styles and a few artist are mapped on a grid of time whereas the color indicates if it was an internal (black) or neighboring (red) influence on Cubism and abstract art. The size of the nouns tells something about the historic relevance. The arrows represent causal paths (which only go in one direction). What it does so well, is focussing on causality and combining multiple sources and levels of data (which happen to be 2 of the principles mentioned in the next paragraph).
Although the causal paths in the art chart are complex, the idea of causality is simplistic.
Principles and pitfalls
After one hundred twenty-one pages of critically analyzing images, 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.
Microsoft Powerpoint and sculptural pedestals..?
Up till now, the structure of the book made perfect sense. From critically analyzing the most amazing images (from Galileo and Da Vinci to medical monitors) and coming up with principles and pitfalls, 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 sudden change of topic might be strange, but 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. He thoroughly explains why powerpoint is contradicting with his principles. He even conducted comparisons of various presentation-tools using ten case-studies in which powerpoint was outperformed by all alternatives. In order to make better presentations we should use ‘good teaching’ as a metaphor in which explanation, reasoning, finding things out, questioning, content, evidence, credible authority not patronizing authoritarianism are the core ideas.
In the last two (short) chapters another rather strange switch of topic is made. These chapters briefly explain how pedestals influence the sculpture they carry, but they mostly consists out of photographs of sculptures (of which half are made by Tufte).
Beautiful Evidence is a typical ‘Tufte-book’, which means that it’s full with beautiful images and photographs, mostly from greats like Galileo, Da Vinci and Newton, which he critically analyzed. To me they’re all very inspirational and often work as eye-openers. They tell a lot about how people interact with and perceive visual information. Furthermore the book is full of principles and pitfalls which I’ve already written on a separate piece of paper to keep in mind for when I have to design analytical visualizations again. All very useful content.
The strange switches of topic make the book feel more or less like a collection of information then a solid coherent read. To me it feels like it does take away some of the strength of the book, however this doesn’t make me like the book any less. The chapter about powerpoint, though unexpected, was an eye-opener and also a very entertaining read.
However, there are some topics in Beautiful Evidence which Tufte has already discussed in his earlier books, which sometimes results in somewhat of a deja vu when reading it. But there’s enough new content to keep me satisfied. I really like it and I would buy the book even if it was just for the critically analyzed images. A incredibly inspirational read.