Graphical excellence is that which gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space.
Edward R. Tufte, The Visual Display of Quantitative Information
Graphical Excellence is further
- the well-designed presentation of interesting data – a matter of substance, of statistics, and of design.
- consists of complex ideas communicated with clarity, precision, and efficiency.
- is nearly always multivariate.
- requires telling the truth about the data.
Graphical Integrity
Tufte spends a lot of time reviewing poor graphics which were printed in major publications. His formula to determine the honesty of a graphic is:
- Lie Factor = size of effect show in in graphic / size of effect in data
As Tufte reviews misleading visualizations, he calculates the Lie Factor on each one.
Chart Design and Data-Ink Maximization
Tufte is a data visualization minimalist. He strives to communicate as much information as possible in as little ink possible. His formula for measuring how effective a visual is at maximizing the ink value is:
- Data-Ink Ratio = data-ink / total ink used to print the graphic
Data-ink is defined as “the non-erasable core of a graphic, the non-redundant ink arranged in response to variation in the
numbers represented.”