Data Visualization Guidelines
Charles Joseph Minard 1969
Modern data visualization often focuses on powerful computer-generated graphics and highly saturated colors. However, one of the most renowned statistical graphics was created in 1861 by Charles Joseph Minard. Depicting Napoleon’s Russian campaign of 1812, Minard captures six variables in a coherent graphic. The width of the line depicts army size with the black line denoting his retreat. The lines are arranged on a two-dimensional map showing military movements and direction. Lastly, temperature is plotted along the bottom exposing losses in the harsh weather. Free of computer-generated graphics and bright colors, Minard demonstrates form and substance are two of the most important elements of a good data visualization.
Tips for Effective Graphics
Show, Don’t Tell
Induce the viewer to think about substance rather than methodology. Printed type should be used sparingly and free of abbreviations and cryptic codes. The visual should be the primary means of communication. If information cannot be communicated clearly and creatively using visuals, the graphic becomes an unnecessary addition.
Avoid unnecessary graphical embellishments and bright, gaudy color schemes. Color palettes should be cohesive and calming. Graphics should primarily communicate the message without unnecessary embellishment. Colors, patterns, and graphics should complement the design rather than compensate for poor visualization design. Computers have enabled a spectrum of customization, but embellishment cannot overcome poor design and planning.
The purpose of a data visualization is to display data in a clear and unique way. Almost everyone can create an excel chart. Good data visualizations incorporate multiple data dimensions. The more information that can be cleanly displayed in a small space, the better. Don’t insult your viewer with a simple graphic, but also don’t confuse with an elaborately cryptic design.