Q Matrix VariablesUse this field to specify those variables containing the columns of the Q matrix ; that is, the matrix containing population assignments. Alternatively, a matrix containing principal components analysis (PCA) assignments can be used (Zhao et al. 2007). These variables are used as fixed effects in the model .To Specify One or More Q Matrix Variables:All of the variables in the specified input data set are displayed in the Available Variables field.
Highlight the desired variables. Left-click a single variable, or hold down while left-clicking to select multiple variables.
Click to add the highlighted variable(s) to the Q Matrix Variables field, as shown below: