Individual Value Plot

Use Individual Value Plot to assess and compare sample data distributions. An individual value plot shows a dot for the actual value of each observation in a group, making it easy to spot outliers and see distribution spread.

In This Topic

Continuous variables
Categorical variables (optional)
Layout
By variables
Jitter individual symbols
Y-scale
Variable display order

For information about data considerations, examples, and interpretation, go to Overview for Individual Value Plot.

Continuous variables

Enter one or more numeric columns that you want to graph.

Categorical variables (optional)

Enter up to five columns of categorical data that define the groups.

Layout

Choose one of the following layout options.

Separate graphs for each continuous variable: Creates a separate individual value plot for each column in the Continuous variables field.
Overlay continuous variables: Columns in the Continuous variables field are overlaid on a single individual value plot.

By variables

Enter one or more grouping variables in By variables to create a separate individual value plot for each level of the grouping variables. The columns that you enter can be numeric or text, and must be the same length as the columns in Continuous variables and Categorical variables. The y-scales for each variable are the same across the multiple individual value plots.

Show all combinations

When you enter multiple By variables, Minitab enables the Show all combinations checkbox. Select this option to create a separate individual value plot 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 individual value plots for Male, Female, Employed, and Unemployed.

Jitter individual symbols

If you have identical data values on your graph, individual symbols could hide behind each other. Choose this option to move symbols slightly to reveal overlapping points.

Y-scale

Select how you want to display the y-scale.

Original units: Use the original units of measure for numeric variables.
Standardized units: Convert different units of measure to a standard unit to make numeric variables comparable.
Same Y-scale: Make the Y-scale the same across multiple graphs.

Variable display order

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.

Categorical variables first, Y's below: Graph variables are the outermost groups and the categorical variables are the innermost groups.
Y's first, categorical variables below: Graph variables are the innermost groups and the categorical variables are the outermost groups.