Dear Prof. Zalesky,

I have read the forum before and it was really helpful in addressing many question. However, now I stuck with the design matrix for the NBS. I need to construct 2 x 2 repated mesures ANOVA design matrix with the age as the covariate to control for. The design has two groups and two time points (sessions). Here is an example of the design matrix for Group1 (3 subjects) and Group2 (2 subjects):

                                                   Age                                                  
Group1 Session1 Subj1  1 0 0 0 0  15.5  1   1               Of note, the real number of subjects in each group is significantly larger.
Group1 Session1 Subj2  0 1 0 0 0  11.2  1   1
Group1 Session1 Subj3  0 0 1 0 0   9.6   1   1
Group1 Session2 Subj1  1 0 0 0 0  15.5 -1  -1
Group1 Session2 Subj2  0 1 0 0 0  11.2 -1  -1
Group1 Session3 Subj3  0 0 1 0 0   9.6  -1  -1
Group2 Session1 Subj4  0 0 0 1 0   7.7   1  -1
Group2 Session1 Subj5  0 0 0 0 1   8.2   1  -1
Group2 Session2 Subj4  0 0 0 1 0   7.7  -1   1
Group2 Session2 Subj5  0 0 0 0 1   8.2  -1   1


I wonder, is this the correct way of adding the covariate? I would be grateful for any help or suggestions.

Best regards,
Maksym