Essay 3: The Principle of Proportional Ink

The Principle of Proportional Ink was originally captured in Edward Tufte’s seminal book The Visual Display of Quantitative Information. In this book, he states that the vast majority of the ink used to create a graphic should be designated to the presentation of the data itself. In other words, there are benefits to limiting the number of tick marks, color filler, grid squares, and other extraneous design that will ultimately detract from the presentation of the data.

Not only can graphs divert attention away from the data, but the addition of unnecessary fillers can lead to the misrepresentation of data as well. The use of 3-D graphics, for instance, almost always skews the viewer’s interpretation of the data and it does not add any value to the image - particularly when it’s set up against markers that should display perfectly straight lines. More often than not, the Y axis become distorted, making it difficult to get accurate information. The same is true of fillers used in line graphs, which runs the risk of overdramatizing your data.

The use of color is also cited in this essay as a big distraction from the presentation of data. Regarding the construction of graphs, they state that “…only the vertical and horizontal positions allow easy and precise comparisons. Color and size are useful to set context for each item.” Human beings cannot derive quantity or even meaning through the use of color on it’s own.  And even in cases where a legend does exist with color coded variables, requiring the data consumer to bounce between an interpreter (legend) and the primary material can lead to fatigue on the part of the consumer. Ultimately, limiting the our inclination as human beings (and artists, perhaps) to over-embellish is necessary when the integrity of the data is at stake.

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