Hi,
Using an F-test is the easiest way to get a two-sided test.
All the best,
Mark
> On 3 Jul 2015, at 17:38, Renske Huffmeijer <[log in to unmask]> wrote:
>
> Hi,
>
> This is probably a very silly question, but I can't seem to find the answer: We've run lower level analyses for each subject that resulted in several copes, and now want to run a higher level analysis to test the group effect (EV1) as well as effects of a continuous variable (EV2). We want to test everything 2-sided and I was wondering how to set up the contrasts. If we'd just include both the positive and negative effect of each EV, we'd be testing 1-sided twice, which isn't quite correct. Can we use F-tests to remedie this or should we half a p-value somewhere?
>
> Thanks!
> Renske
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