Tufte's Fundamental Principles

800px-Minard
800px-Minard

1: Comparisons Show comparisons, contrasts, and differences. The fundamental analytical act in statistical reasoning is to answer the question “Compared to what?”

2: Causality Show causality, mechanism, explanation, and systematic structure.  How was the information that is represented caused? What are the sources of differences and variability in the measurements?

3 Multivariate Analysis Show multivariate analysis; that is show more than 1 or 2 variables. Depicting the conditions under which a cause and effect occur quickly becomes multivariate. We live in a profoundly multi-dimensional world so escape from the 2-D flatland of paper and computer screen.

4 Integration of Evidence Completely integrate words, numbers, images, diagrams, graphics, charts, etc. Sound inferences are rarely made by distinguishing among different modes of evidence. What maters entirely is the evidence, not the particular mode of evidence.

5 Documentation Thoroughly describe the evidence. Provide a detailed title, indicate the authors and sponsors, document the data sources, show complete measurement scales, point out relevant issues. Credibility, bias, and responsibility of authorship must be taken into account when accessing evidence.

6 Content Counts Most of All Analytical presentations ultimately stand and fall depending on the quality, relevance, and integrity of their content. Gratuitous design devices (“chart junk”) cannot salvage failed content.