
Hi,
I have an experiment where I measured two times the dependent variable (called <b>Intention</b>). So, I have IntentionPre and IntentionPost.
I am working with an anova for an independent variable called <b>NumberOfModules</b>.
The problem is that if I run the aov(intentionpre~NumberOfModules) I have that there is a significant difference between the means.
I want to know the difference between pre and post intentions based on the NumberOfModules. So, I've been told that I should make an ancova and the IntentionPre variable will work as a covariable, but I don't really know how should organize my data in order to get that.
My dataframe currently has the following columns: <b>Email (userId), Intention (pre+post values), constrast (is it pre or post value?), and NumberOfModules.</b>
What I would do if there were no significant difference between the means for the <b>intentionpre</b>, would be:
<i>aov(intention~constrats*NumberOfModules+Error(Email/constrats), gdataframe)</i>
What I was thinking to do is adding a column with  <b>IntentionPre</b> (duplicated for every pre and post value for the <b>Intention</b> column) and running it like:
<i>aov(intention~intentionPre + constrats*NumberOfModules+Error(Email/constrats), gdataframe)</i>
Is that a correct reasoning?
Any help would be great!!

Camilo V 		 	   		  
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