Principles of Analytical Design

In the fifth chapter of Beautiful Evidence, Edward Tufte uses Charles Minard’s flow map to describe six Principles of Analytical Design.

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The visualization is a Figurative map of the successive losses in men of the French Army in the Russian campaign 1812-1813. Minard displays six variables in different visual encodings: the size of the army, its two-dimensional location (latitude and longitude), the direction of the army’s movement, and temperature on various dates during the retreat from Moscow.

The six Principles described in the Book are:

1. Comparisons - Show comparisons, contrasts, differences.

2. Causality, Mechanism, Structure, Explanation - Show causality, mechanism, explanation, systematic structure.

3. Multivariate Analysis - Show multivariate data; that is show more than 1 or 2 variables.

4. Integration of Evidence - Completely integrate words, numbers, images, diagrams.

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.

6. Content Counts Most of All - Analytical presentations ultimately stand or fall depending on the quality, relevance and integrity of their content.

Can you spot those principles in Minard’s Map?