The Boxplot is a typical frequency plot containing a lot of information in the graph. It is a graphical analysis tool used to investigate the effect of discrete inputs (X) on continuous outputs (Y).

Graphical Interpretation:
– The box contains 50% of all the data (from 1st to 3rd Quartile)
– The “whiskers” go from the box to the min / max value. When min / max or other values are more than 1.5 times of the box size away from the 1st / 3rd quartile those are not included in the whisker but displayed as asterix.

Attention: A Boxplot does the same for small and large samples, i.e. the visual impression is misleading for small samples (you can add the individual values to your Boxplot to compensate).

Read also: Histogram, Dotplot