For information about data considerations, examples, and interpretation, go to Overview of Boxplot.
Enter one or more numeric columns that you want to graph.
Enter up to five columns of categorical data that define the groups. The first variable is the outermost on the scale and the last variable is the innermost.
Choose one of the following layout options.
When you enter multiple By variables, Minitab enables the Show all combinations checkbox. Select this option to create a separate boxplot for each combination of groups created by the By variables. If you do not select this option, Minitab creates a plot for each group of each By variable.
For example, the first By variable has 2 groups, Male and Female, and the second By variable has 2 groups, Employed and Unemployed. If you select Show all combinations, Minitab creates 4 separate plots for the combinations of Male/Employed, Male/Unemployed, Female/Employed, and Female/Unemployed. If you do not select Show all combinations, Minitab creates 4 separate boxplots for Male, Female, Employed, and Unemployed.
The whiskers extend from either side of the box. The whiskers represent the ranges for the bottom 25% and the top 25% of the data values, excluding outliers.
With large data sets, where outliers are common, you can display custom percentiles instead of outliers to gather more information about the data. Custom percentiles occur outside of the interquartile box and typically occur in the tails of the distribution. In addition, lines are placed at the minimum and maximum values. By default, these percentile values are 0.5, 2.5, 10, 90, 97.5, and 99.5, but you can add, delete, or change them.
Select how you want to display the y-scale.
Minitab uses the terms "innermost" and "outermost" to indicate the relative position of the scales for multiple levels of groups displayed on a graph. For a horizontal scale, outermost refers to the scale at the bottom of the graph, and innermost refers to the scale farthest from the bottom, closest to the horizontal axis. For a vertical scale, outermost refers to the scale to the far left, and innermost refers to the scale closest to the vertical axis.
Choose one of the following options when you have multiple Y variables with groups.