How do we read a violin plot?


#1

Question

In the context of this exercise, how do we read a violin plot to determine its distribution type?

Answer

When reading a violin plot, the distributions are essentially just rotated vertically rather than horizontally, and then mirrored on the left and right sides.

To read the distributions from a violin plot, we just need to reverse these steps. We can rotate the plots so that the values are on the x axis, and in increasing order from left to right. Then, you can ignore the mirrored side below the x axis, and read the distribution shape as you normally would, for the top half.

Keeping this in mind, we can determine the shapes of the example violin plots in the exercise:

Dataset 1 (Blue) is unimodal and has most of its data on the right, so it must be skewed left.

Dataset 2 (Green) is unimodal and seems to be symmetric and normal.

Dataset 3 (Red) appears to be bimodal.