Planned Contrast Coding Question

Posted by Baglioni, Tony on May 08, 2015; 2:18pm
URL: http://spssx-discussion.165.s1.nabble.com/Planned-Contrast-Coding-Question-tp5729543.html

All

 

I have a question regarding a study utilizing the below 2 x 4 between-subjects design. 

 

	Variable Y
Variable X	Y1	Y2	Y3	Y4
X1	A	B	C	D
X2	E	F	G	H

 

In order to respond to a reviewer’s concern, we need to test the following ordered interaction:

 

Participants in condition Y4 are less likely than those in condition Y3 who are less likely than those in condition Y2 to engage in an action and this effect is greater under X2 than X1.

 

[(B > C > D) < (F > G > H)

 

We currently are using the following contrast coding to test for this planned contrast, but I just don’t know if it’s correct given that we want to ignore the No FW (Y1) condition.

 

/lmatrix 'why less likely than hybrid which is less likely than pro/con to allow aggressive reporting and this effect is greater under less precise standards'  standard*framework 0 1 0 -1 0 -1 0 1

 

	No FW	Pro/Con	Hybrid	Why
More precise	0	1	0	-1	0
Less precise	0	-1	0	1	0
	0	0	0	0

 

Any help is much appreciated.

Tony

 

A J Baglioni jr

Associate Professor

McIntire School of Commerce

343 Rouss/Robertson Hall

University of Virginia

434.924.4961

 

 

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