Re: Simple Main Effects Pairwise Comparisons vs Univariate Tests

Posted by Art Kendall on Jun 05, 2014; 12:20pm
URL: http://spssx-discussion.165.s1.nabble.com/Simple-Main-Effects-Pairwise-Comparisons-vs-Univariate-Tests-tp5726323p5726356.html

"There was one experimental group and two control groups."

Are these actually "experimental" and "control" groups? I.e., was group membership assigned by a random process?

Or were these "treatment" and comparison groups?

If the latter what defines the groups?

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Plot the 9 means with time on the horizontal (X) axis, the DV on the vertical (Y) axis, with the points for groups connected.

By eye, do the lines appear very far from parallel?  Is there a visually clear difference in the changes?

Add vertical error wings to the points, eyeball the parallelism again. What do you see?