Hi metaSEM users, hi Mike,
I enjoy using the metaSEM package for my analysis in R. I amjust wondering how I can compare path cofficients in an estimated model (t-test) ? Probably it is quite easy, but I am new to R. So help is really appreciated :)
Thanks
Johannes
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Hi Johannes,
You may use the same label if you want to have the same parameter estimates. Then you can compare the models by using the anova() function. For example,
fixed1 <- tssem1(Becker94$data, Becker94$n, method="FEM")
summary(fixed1)
Different regression coefficients
A1 <- create.mxMatrix(c(0,"0.2Spatial2Aptitude","0.2Verbal2Aptitude",
0,0,0,
0,0,0), type="Full",
ncol=3, nrow=3, byrow=TRUE, name="A1")
S1 <- create.mxMatrix(c("0.2ErrorVarAptitude",
0,1,
0,"0.2CorBetweenSpatialVerbal",1),
type="Symm", byrow=TRUE, name="S1")
fixed2a <- tssem2(fixed1, Amatrix=A1, Smatrix=S1,
model.name="Different regression cofficients")
summary(fixed2a)
Same regression coefficient
A2 <- create.mxMatrix(c(0,"0.2Aptitude","0.2Aptitude",
0,0,0,
0,0,0), type="Full",
ncol=3, nrow=3, byrow=TRUE, name="A1")
fixed2b <- tssem2(fixed1, Amatrix=A2, Smatrix=S1,
model.name="Same regression cofficient")
summary(fixed2b)
Compare these two models with a chi-square difference test
anova(fixed2a, fixed2b)
Mike
Hi Mike,
Thanks for your quick answer. Then I will try the model comparisons. I thought there might be something like the test in MPlus that tests c1 = c2 within a model.
Johannes
Interestingly, it works but I am not really sure with the results.
When I compare the models with the coefficients of .124*** and -.037 (differnt vs. same), they are not significantly different. Can that be?