A box plot displays robust statistical parameters: minimum, lower quartile, median, upper quartile, and maximum. A box plot for one numerical attribute is constructed in the following way: The box itself goes from lower quartile (Q1) to upper quartile (Q3). Median is drawn as horizontal bar inside box. Distance between Q1 and Q3 is called interquartile range (IQR). Above and below box are so-called whiskers. They are drawn at minimum and maximum value as horizontal bars and are connected with the box by a dotted line.