Statistics > Box Plot

Box Plots

In 1977, John Tukey published an efficient method for displaying a five-number data summary. The graph is called a boxplot (also known as a box and whisker plot) and summarizes the following statistical measures:

The following is an example of a boxplot.

Box Plot

The plot may be drawn either vertically as in the above diagram, or horizontally.

Interpreting a Boxplot

The boxplot is interpreted as follows:

Boxplot Enhancements

Beyond the basic information, boxplots sometimes are enhanced to convey additional information:

Advantages of Boxplots

Boxplots have the following strengths:

One drawback of boxplots is that they tend to emphasize the tails of a distribution, which are the least certain points in the data set. They also hide many of the details of the distribution. Displaying a histogram in conjunction with the boxplot helps in this regard, and both are important tools for exploratory data analysis.

Statistics > Box Plot

Search NetMBA

Site Information
  Terms of Use


Accounting   Economics   Finance   Management
Marketing   Operations   Statistics   Strategy