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help > RE: 2-by-3 repeated measures ANOVA
Mar 3, 2022 07:03 AM | Andrew Zalesky
RE: 2-by-3 repeated measures ANOVA
Hi Konstantinos
the design matrix is not correct and will be rank deficient.
Some quick points:
- To test the effect of group, a repeated measure is not needed, because the group will remain the same for all repeated measures. A person that is ASD in condition 1 will still be ASD in condition 2, etc. So, for the main effect of group, you can simply average the FC matrices across the repeated measures or separately test for a group effect for each emotion condition.
- Check out some of the previous posts here where I have described in detail the design matrix for a 2 x 2 repeated measures ANOVA. It should be possible to extend the design to a 2 x 3 design.
- The interaction term would be determined by multiplying the group column by the relevant emotion condition column.
- The group effect column must be removed from the design matrix (see first point).
So your design matrix would have two columns for any two of the three conditions, two columns for interaction terms and columns for the within-subject means.
best,
Andrew
Originally posted by Konstantinos Tsilimparis:
the design matrix is not correct and will be rank deficient.
Some quick points:
- To test the effect of group, a repeated measure is not needed, because the group will remain the same for all repeated measures. A person that is ASD in condition 1 will still be ASD in condition 2, etc. So, for the main effect of group, you can simply average the FC matrices across the repeated measures or separately test for a group effect for each emotion condition.
- Check out some of the previous posts here where I have described in detail the design matrix for a 2 x 2 repeated measures ANOVA. It should be possible to extend the design to a 2 x 3 design.
- The interaction term would be determined by multiplying the group column by the relevant emotion condition column.
- The group effect column must be removed from the design matrix (see first point).
So your design matrix would have two columns for any two of the three conditions, two columns for interaction terms and columns for the within-subject means.
best,
Andrew
Originally posted by Konstantinos Tsilimparis:
Hi Dr. Zalesky,
I have two groups (ASD, control) of 19 and 23 subjects and three conditions (angry, happy, neutral).
I would like to use a 2-by-3 repeated measures ANOVA model group (ASD, control) as a between-subjects factor and emotion (angry, happy, neutral) as a within-subjects factor.
I want to test the main effect of group on functional connectivity, the main effect of emotion, and the group-by-emotion interaction.
I have prepared the following design matrix and I was hoping if you could confirm that it is correct.
For simplicity I show you only the design matrix for the 2 first subjects of every group.
1 0 1 0 0 1 0 0 0
1 0 0 1 0 1 0 0 0
1 0 0 0 1 1 0 0 0
1 0 1 0 0 0 1 0 0
1 0 0 1 0 0 1 0 0
1 0 0 0 1 0 1 0 0
0 1 1 0 0 0 0 1 0
0 1 0 1 0 0 0 1 0
0 1 0 0 1 0 0 1 0
0 1 1 0 0 0 0 0 1
0 1 0 1 0 0 0 0 1
0 1 0 0 1 0 0 0 1
where:
Column1: ASD
Column2: CONTROL
Column3: ANGRY
Column4: HAPPY
Column5: NEUTRAL
Column6: Subject 1 '
Column7: Subject 2
Column8: Subject 3
Column9: Subject 4
Also, what contrast should I use for an F-test?
Best regards,
Konstantinos
I have two groups (ASD, control) of 19 and 23 subjects and three conditions (angry, happy, neutral).
I would like to use a 2-by-3 repeated measures ANOVA model group (ASD, control) as a between-subjects factor and emotion (angry, happy, neutral) as a within-subjects factor.
I want to test the main effect of group on functional connectivity, the main effect of emotion, and the group-by-emotion interaction.
I have prepared the following design matrix and I was hoping if you could confirm that it is correct.
For simplicity I show you only the design matrix for the 2 first subjects of every group.
1 0 1 0 0 1 0 0 0
1 0 0 1 0 1 0 0 0
1 0 0 0 1 1 0 0 0
1 0 1 0 0 0 1 0 0
1 0 0 1 0 0 1 0 0
1 0 0 0 1 0 1 0 0
0 1 1 0 0 0 0 1 0
0 1 0 1 0 0 0 1 0
0 1 0 0 1 0 0 1 0
0 1 1 0 0 0 0 0 1
0 1 0 1 0 0 0 0 1
0 1 0 0 1 0 0 0 1
where:
Column1: ASD
Column2: CONTROL
Column3: ANGRY
Column4: HAPPY
Column5: NEUTRAL
Column6: Subject 1 '
Column7: Subject 2
Column8: Subject 3
Column9: Subject 4
Also, what contrast should I use for an F-test?
Best regards,
Konstantinos
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| Title | Author | Date |
|---|---|---|
| Konstantinos Tsilimparis | Mar 2, 2022 | |
| Konstantinos Tsilimparis | May 13, 2022 | |
| Konstantinos Tsilimparis | May 11, 2022 | |
| Andrew Zalesky | May 13, 2022 | |
| Konstantinos Tsilimparis | May 13, 2022 | |
| Andrew Zalesky | May 13, 2022 | |
| Andrew Zalesky | Mar 3, 2022 | |
| Konstantinos Tsilimparis | Mar 28, 2022 | |
| Andrew Zalesky | Mar 29, 2022 | |