Day: January 24, 2026

The “dots” at the end of the boxplot represent outliers. There are a number of different rules for determining if a point is an outlier, but the method that R and ggplot use is the “1.5 rule”. If a data point is: less than Q1 – 1.5*IQR greater than Q3 + 1.5*IQR then that point is classed as an “outlier”. The whiskers are defined as: upper whisker = min (max (x), Q_3 + 1.5 * IQR) lower whisker …