JISCMail - FSL Archives

Hi Maren,

In addition to the case of variances not assumed to be the same as Jeanette commented, this setting can also be used in randomise to define exchangeability groups/blocks, which can be used with certain multivariate or longitudinal designs. So, it is an useful setting. There will be some documentation about this soon I hope.

All the best,
Anderson

2013/5/22 Jeanette Mumford <[log in to unmask]>

Hi,

In my experience it may only be an advantage for very large sample sizes. Otherwise, since it is defining groups in which separate between-subject variances will be estimated, these estimates have lower df and may be highly variable. Using one group only gives a single between-subject variance estimate, but it should be a better estimate.

Cheers,
Jeanette

On Wed, May 22, 2013 at 9:12 AM, Maren Strenziok <[log in to unmask]> wrote:

Hi,
I was wondering in which case it is appropriate to use the Group column in the Glm that is left from the first EV? I ask because I thought it might be usful to set up a design with independent groups, which does not seem to be the case according to the FSL Wiki.

Maren