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help > RE: ANCOVA matrix design
Dec 2, 2014 11:12 PM | Andrew Zalesky
RE: ANCOVA matrix design
Hi Matthieu,
The design matrix for an ANCOVA with 3 groups, 2 subjects per group and one covariate would look something like this:
1 1 0 4.53
1 1 0 3.90
1 0 1 2.10
1 0 1 9.43
1 0 0 6.98
1 0 0 8.88
The first column is the intercept. The 2nd is group 1. The 3rd is group 2. The 4th is your covariate.
The contrast is: [0 1 1 0]
The test to select is "F-test"
You should be able to extrapolate this to 5 groups.
Andrew
Originally posted by Matthieu Vanhoutte:
The design matrix for an ANCOVA with 3 groups, 2 subjects per group and one covariate would look something like this:
1 1 0 4.53
1 1 0 3.90
1 0 1 2.10
1 0 1 9.43
1 0 0 6.98
1 0 0 8.88
The first column is the intercept. The 2nd is group 1. The 3rd is group 2. The 4th is your covariate.
The contrast is: [0 1 1 0]
The test to select is "F-test"
You should be able to extrapolate this to 5 groups.
Andrew
Originally posted by Matthieu Vanhoutte:
Dear NBS's experts,
I have one study with 5 groups of 10 subjects for each one. For each subject I have one connectivity matrix. I also have three covariates. I would like to compare these connectivity matrices between the 5 groups. One suggested me to choose an ANCOVA model.
But I don't know what design should have my design matrix with ANCOVA model ? Could you explain me the theoretical design of my design matrix ?
And how should be defined my contrasts to get the effects of groups ?
Many thanks in advance !
Best regards,
Matthieu
I have one study with 5 groups of 10 subjects for each one. For each subject I have one connectivity matrix. I also have three covariates. I would like to compare these connectivity matrices between the 5 groups. One suggested me to choose an ANCOVA model.
But I don't know what design should have my design matrix with ANCOVA model ? Could you explain me the theoretical design of my design matrix ?
And how should be defined my contrasts to get the effects of groups ?
Many thanks in advance !
Best regards,
Matthieu
Threaded View
| Title | Author | Date |
|---|---|---|
| Matthieu Vanhoutte | Dec 2, 2014 | |
| Andrew Zalesky | Dec 2, 2014 | |
| Matthieu Vanhoutte | Dec 3, 2014 | |
| Matthieu Vanhoutte | Dec 10, 2014 | |
| Andrew Zalesky | Apr 16, 2015 | |