# By Variables

Use this field to specify one or more BY variables from ADSL to use in your analysis. Separate analyses are conducted for distinct levels of BY Group variables. Separate plots are generated for each BY group.

### BY Variables

BY variables are optional (in most reports) variable specifications whose values define groups of observations, such as hour, month, or year. BY variables can enable analyses to be performed separately on different groups as defined by that variable. Choosing a BY variable such as gender (ADSL variable = SEX), for example, groups the subjects by gender and conducts two separate analyses: one for males and one for females.

Alternatively, specifying a BY variable enables you to animate an image so that you can see how response values change according to some grouping, like over time.

### To Specify One or More BY Variables:

| 8 | Click to open the Add window (shown below) that lists each variable contained in domain and SUPPxx (if merged) specific to this report

Note: In Demographics Distribution only, variables are taken from ADSL, in addition to the report-specific DS and SUPPPDS (if available) data sets.

| 8 | Select the variables you want to include in the analysis and click to add those variables to the text box.

In this example, AGE, RACE, and SEX were selected and added.

Note: If no BY variables are specified, the analysis is conducted across all the subjects