Deciding on test and help with power, thank you!

[Amber]

Hi there,

I'm a first year PhD student and I am a bit at a loss regarding which test to use, and how to calculate power for a grant proposal. Any help will be much appreciated!

I'm running all my participants in two conditions (positive/negative), so a within-subject design

My dependent variable is continuous

I'm looking at a moderator effect, the moderator being continuous also

So I'm basically seeing if the the effect of condition on my dependent variable is moderated by a continuous variable

I can't seem to figure out which test to use.

Thanks in advance

 

[hlsmith]

Add some more details, I got confused on what you were trying to do. Might help if you provide context.

 

[Amber]

Thanks for responding!

I'm exposing all my subjects to both conditions of a mood induction, a positive and a negative condition. I'm seeing the effect the mood induction has on self reported affect, and I am expecting the relationship between the mood induction and self reported affect to be moderated by a third variable (which is a continuous variable). I'm wondering which statistical test I should use. Please let me know if you have any more questions.

 

[hlsmith]

Will you have baseline data (equivalent to no intervention), and are you describing a crossover design, which you also want to examine a effect modifier?