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Dear AFNI users-
We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:
Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.
The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.
Sincerely, AFNI HQ
We are very pleased to announce that the new AFNI Message Board framework is up! Please join us at:
https://discuss.afni.nimh.nih.gov
Existing user accounts have been migrated, so returning users can login by requesting a password reset. New users can create accounts, as well, through a standard account creation process. Please note that these setup emails might initially go to spam folders (esp. for NIH users!), so please check those locations in the beginning.
The current Message Board discussion threads have been migrated to the new framework. The current Message Board will remain visible, but read-only, for a little while.
Sincerely, AFNI HQ
| September 19, 2017 03:22PM | |
Hi, I have a question for Gang.
I have a skewed quantitative variable I am trying to include in my model. The variable is a factor score from a CFA, and has a mean of 0.05, but it is very heavily skewed. Following are pictures of its boxplot and histogram. I am trying to model a dataset of twins, so I have to use 3dLME. I have two questions:
1) Is 3dLME robust to violations of normality in quantitative variables? If not, what are some transformations we can do to the data in order to make it work?
2) When we specified the CFA, we fixed means at 0 and residual variances at 1. Our thought initially was to specify the centering at 0. But given the skewness of this variable, should we be taking a different approach to thinking about centering?
Thank you very much!!
I have a skewed quantitative variable I am trying to include in my model. The variable is a factor score from a CFA, and has a mean of 0.05, but it is very heavily skewed. Following are pictures of its boxplot and histogram. I am trying to model a dataset of twins, so I have to use 3dLME. I have two questions:
1) Is 3dLME robust to violations of normality in quantitative variables? If not, what are some transformations we can do to the data in order to make it work?
2) When we specified the CFA, we fixed means at 0 and residual variances at 1. Our thought initially was to specify the centering at 0. But given the skewness of this variable, should we be taking a different approach to thinking about centering?
Thank you very much!!
| Subject | Author | Posted |
|---|---|---|
|
vumeyer | September 19, 2017 03:22PM |
|
gang | September 20, 2017 05:55PM |
