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<TITLE>setParameter and interactions between the behavior and attribute variables in the selection part </TITLE>
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<P><FONT SIZE=2>Dear m,<BR>
<BR>
I've got 3 questions<BR>
1. I'm trying do make interactions in the influence part of the model using:<BR>
<BR>
myeff[myeff$effectName=='behavior roken: influence interaction2'& myeff$type=='eval', 'include' ]=TRUE<BR>
<BR>
were interaction2 is the attribute variable SES, but it doesn't work.<BR>
I know I have to set the ‘parm’ column on 1 2 or 3, but how do I do this using R function without the GUI?<BR>
I also tried for the selection part:<BR>
<BR>
myeff <- includeInteraction(myeff, egoX, recip,interaction1="ses")<BR>
myeff <- setParameter(myeff, outInv, 3)<BR>
but R gives me the following massage:<BR>
Error: could not find function "setParameter"<BR>
<BR>
2. I want to do make an interaction between an attribute variable and the behavior variable<BR>
in the selection part of the model.<BR>
to exemplify: I try to test the hypothesis: smoking students from lower SES backgrounds have a stronger preference for smoking friends.<BR>
Is it possible to program that? I tried to make a changing covariate SESxsmoking, but I only have to waves, and according to the tutorial (page 28) that doesn’t make sense. So I figured that I make a interaction SESxsmoking on basis of the smoking scores of the first wave and use it as a covariate. But I have a feeling that this is not correct.<BR>
<BR>
<BR>
3. I would like to use dummies as is usual in ols regression in the influence part of the model for the main effects of an attribute variable. Does this work in the same way as in ols regression, in the sense that I have to leave out one reference category?<BR>
Important to know is that I cannot use the fix(myeff), I have to edit the dataframe directly with R functions.<BR>
I hope you can help me out.<BR>
<BR>
Best regards,<BR>
<BR>
<BR>
<BR>
<BR>
<BR>
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