Chapter 13 Malicious Uses of Data
This will showcase many examples of people using data and graphics fraudulently.
13.1 Dual Y-Axes
In general, dual y-axes are hard to do correctly, and can be easily used maliciously.
Lisa Charlotte Rost has a great example of how the arbitrary scaling of each axis results can result in unintentionally confusing graphs.
In particular, the relative percent change or the rate of change is now messed up because the slopes on the two axes are not equivalent. Malicious tweaking of the scales would allow us to show whatever we want.
Example. Market share of a particular cookie manufacturer.