I am having a few problems with my analysis and hope that somebody can help me out. About my design: I have 120 respondents, who I showed each 7 facebook posts out of a pool of 16 (randomly assigned). Each facebook posts was "ranked" by them on 1 DV (shares) and 3 IV (entertainment, information and emotion).
Due to the repeated measures design I decided to use ANCOVA and include "participant" as a factor, controlling for general differences among participants (so 'groups'), and my three IV's as covariates. I am not interested in group differences though. Up to now makes sense, doesnt it? I could also perform a linear regression but it would be kind of crazy to create a dummy for 120 participants?
Now I have the problem that I dont meet the assumptions. If I check for interactions between the factor (participants) and IV's, they are all significant. And in a model with participant as factor and the three covariates, the Levene's test is significant as well...Nevertheless, overall there is a linear relationship between DV and IV's. But each group is only 7 responses, this may be too small?
Anybody knows why and can help? Since I use ANCOVA for another purpose than most of the people anyway, I am not sure if I can ignore the violations or how I can help it.
Highly appreciate any help!! :) Wiebke