## Edward Tufte

## Graphical excellence

**Communicating complex ideas with clarity, precision, and efficiency**

## Graphical excellence

**Communicating complex ideas with clarity, precision, and efficiency**

- Well-designed presentation of interesting data
- Gives to the viewer the greatest number of ideas in the shortest time with the least ink in the smallest space
- Multivariate
- Requires telling the truth about data

## Graphical integrity

**Tell the truth about the data**

## Graphical integrity

**Wilke’s Principle of Proportional ink**

The representation of numbers, as physically measured on the surface of the graphic itself, should be directly proportional to the numerical quantities represented

## Graphical integrity

**Perceptions of length and area do not match** (and we’re bad at judging area)

## Data-ink ratio

Data-ink: the non-erasable core of a graphic, the non-redundant ink arranged in response to variation in the numbers represented

Data-ink ratio: amount of data-ink divided by total ink used to print the graphic

## Data-ink ratio

- Above all else show the data
- Maximize the data-ink ratio
- Erase non-data-ink
- Erase redundant data-ink

## Chartjunk

Non-data-ink or redundant data-ink that does not tell the viewer anything new