Edward Tufte's Principles for the Analysis and Presentation of Data

1. Show comparison, contrasts, differences. Compared to what? Evaluate. Make intelligent and appropriate comparisons.
2. Show causality, mechanism, explanation, systematic structure. Explain why.
3. Show multivariate data. The only thing that is two dimensional about evidence is the presentation. We live in a multivariate world (3+ dimensions/variables).
4. Completely integrate words, numbers, images, diagrams. How can something be explained? Integrate the diversity of evidence. Present all relevant evidence regardless of mode.
5. Documentation. Thoroughly describe the evidence, provide detailed title, authors, sponsors. Document the data sources, show complete measurement scales, point out relevant issues. Transparency equals trust.
6. Content matters most of all. Analytical presentations ultimately stand or fall depending on the quality, relevance and integrity of their content.

“These summary statements reflect the universal analytic issues of (1) causality, (2) comparison, and (3) multivariate complexity. Human activities, after all, take place in intensely comparative and multivariate contexts filled with causal ideas: intervention, purpose, responsibility, consequence, explanation, intention, action, prevention, diagnosis, strategy, decision, influence, planning.”

— Edward Tufte, Beautiful Evidence