Variables Defining Control Sets

When using multiple sets of control samples, you must specify a subset of the columns entered in the {link}{Emphasis}Variables Defining Analysis Groups field that define the analysis groups that should be used as control sets. The samples for which the control sets are used in reference to are decided by the distinct groups made by the variables in the Variables Defining Analysis Groups field that were not re-specified as Variables Defining Control Sets. The values for these columns that indicate a sample as a control should be entered in the {link}{Emphasis}Control Levels field.

Important: These columns must be specified in the {link}{Emphasis}Variables Defining Analysis Groups field to avoid errors.

For an example, with the Drosophila Aging example, if you want to use males as the controls for females that are matched for Line and Age: specify Line, Sex, and Age as the Variables Defining Analysis Groups and specify Sex in the Variable Defining Control Sets field (with "MAL" as the Control Level in the field below). This designates the values "ORE", "MAL", and "WK1" as controls for samples with Line="ORE" and Age="WK1", and designates the values "SAM", "MAL", and "WK1" as controls for samples with Line="SAM" and Age="WK1". Likewise, the controls for Line="ORE" and Age="WK6" would be samples with values "ORE", "MAL", and "WK6", and the controls for Line="SAM" and Age="WK6" would be samples with values "SAM", "MAL", and "WK6" for Line, Sex, and Age, respectively.

For more complex designs, such as nested designs, or designs where the value of the control changes across analysis groups, it might be necessary to construct a new column to be included in the Variables Defining Analysis Groups and the Variables Defining Control Sets in the {link}{Emphasis}Experimental Design SAS Data Set to indicate the analysis groups that should be used as controls.

To Specify Variables Defining Control Sets:

8 Specify an {link}{Emphasis}Experimental Design SAS Data Set.

The Available Variables field is populated with variables from the specified data set.

8 Left-click a single variable, or hold down while left-clicking multiple variables, from the Available Variables field.
8 Click to add the selected variable(s) to the Variables Defining Control Sets field.