Adjusting

Non-data Ink

Remove non-data ink and optimize data-ink

Non-data ink, like the border around the plot, does not add useful information and can be removed. Data ink, such as the axes tick marks do not encompass the entire data set, and so can be extended. In addition, the axes labels should provide details like the units.

Adjust the aspect ratio appropriately

Jittering, removal of unnecessary non-data ink, and an aspect ratio of 1.

Choosing an inappropriate aspect ratio can distort the visual representation of the data. In the worst-case, emphasising weak trends and obscuring troublesome aspects in this manner can be considered unethical. Even in the best-case, you will not effectively communicate your results if you use an inappropriate aspect ratio.

Here we have a clear choice for choosing an appropriate aspect ratio. Since both variables are on the same scale (i.e. measured in centimetres), the only logical choice is that the physical scales are also the same. That is, if 1.0 cm sepal width (scale) is drawn as 0.5 cm on paper (physical) then this should also be the case for sepal length.