Visual and Statistical Thinking is a “textbooklet” by Edward Tufte that Lorna got me (along for a replacement for my missing The Cognitive Style of PowerPoint. It looks closely at two examples of how graphs were used to think through a problem in order to recommend action; first John Snow’s analysis of the Broad Street cholera epidemic, and then the decision to launch the space shuttle Challenger. Tuftewrites that his “general argument is straightforward”:
An essential analytic task in making decisions based on evidence is to understand how things work – mechanism, trade-offs, process and dynamics, cause and effect. That is, intervention-thinking and policy-thinking demand causality-thinking.
Making decisions based on evidence requires the appropriate display of that evidence. Good displays of data help to reveal knowledge relevant to understanding mechanism, process and dynamics, cause and effect. That is, displays of statistical data should directly serve the analytic task at hand. (p. 3, copyright 1997, Graphics Press, Cheshire, Connecticut).
Text visualization in the humanities is not, however meant to guide decisions. Literary analysis guides interpretation which does not lead immediately or causally to decisions. What then is point of interpretative analysis (visual or not)? An extreme view would be that it is an art; the art of creating new aesthetic works of a particular genre called intepretation that stand in a particular relationship with other works. Interpretations are made or crafted from abstract matter, namely other works of art. Their appreciation is predicated on knowledge of the “original”.
Tufte ends his textbooklet with some concrete recommendations for the graphic display which include:
- “documenting the sources and characteristics of data”
- “enforcing appropriate comparisons“
- “demonstrating mechanisms of cause and effect“
- and “inspecting and evaluating alternative explanations.”
(p. 31, note that I have left some of his principles out.) Another point he makes repeatedly is that it is more important to get it right than to be original in design. Here is where aesthetic visualization parts from decision making – art aims at originality not rightness.
I should also mention that on Tufte’s site there is an excellent section I just discovered called Ask E.T.. Rather than set up a discussion forum, it is organized around questions posed by others to which Tufte (and others) can post answers. Wandering through some of these questions and follow up discussions one finds recurring themes, especially as multimedia designers struggle with Tufte’s thinking and how to apply it to a medium that is low resolution but capable of animation. Tufte does a great job of resisting an easy appropriation of his thought into hypermedia design.