Hi all!
Let me ask you something basic about interactions. I did a lot of runs on some data here and noticed the results show great variation depending on how many interactions I add to the model. Interactions, whether sensible or not, always strongly change the outcome for the contrasts of the main EVs, too - by their mere existence! On group level, in comparison to the run without interactions, sometimes some clusters completely disappear and others show up in entirely different regions. Does that make sense? And if so, which runs are more valid, the ones with, or without interactions?
Thanks!
Georg
|