A colleague of Galileo, Federico Cesi, wrote that Galileo's 38 hand-drawn images of sunspots "delight both by the wonder of the spectacle and the accuracy of expression." That is beautiful evidence.
Evidence that bears on questions of any complexity typically involves multiple forms of discourse. Evidence is evidence, whether words, numbers, images, diagrams, still or moving. The intellectual tasks remain constant regardless of the mode of evidence: to understand and to reason about the materials at hand, and to appraise their quality, relevance, and integrity.
Science and art have in common intense seeing, the wide-eyed observing that generates empirical information. Beautiful Evidence is about how seeing turns into showing, how empirical observations turn into explanations and evidence presentations. The book identifies excellent and effective methods for presenting information, suggests new designs, and provides tools for assessing the credibility of evidence presentations.
Evidence presentations are seen here from both sides: how to produce them and how to consume them. As teachers know, a good way to learn something is to teach it. The partial symmetry of producers and consumers is a consequence of the theory of analytical design, which is based on the premise that the point of evidence displays is to assist the thinking of producer and consumer alike. Evidence presentations should be created in accord with the common analytical tasks at hand, which usually involve understanding causality, making multivariate comparisons, examining relevant evidence, and assessing the credibility of evidence and conclusions. Thus the practice of evidence display are derived from the universal principles of analytical thinking—and not from local customs, fashion, consumer convenience, marketing, or what the technologies of display happen to make available. The metaphor for evidence presentations is analytical thinking.
Making an evidence presentation 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.
Here we will see many close readings of serious evidence presentations—ranging through evolutionary trees and rocket science to economics, art history, and sculpture. Insistent application of the principles of analytical thinking helps both insiders and outsiders assess the credibility of evidence.
