I am running a pathway analysis in Lavaan and am trying to compute post-hoc power using G*Power 3. Here is the model I have run and part of the output:
model2 <- '
AASP_SAvo ~ SRS_T + BPQ_T
AASP_SSens ~ SRS_T + BPQ_T
BPQ_T ~ SRS_T
TAS_T ~ SRS_T + AASP_SAvo + AASP_SSens + BPQ_T
IUS_comp ~ SRS_T + TAS_T
CERQ_Negative ~ TAS_T
LSAS_T ~ SRS_T + AASP_SAvo + AASP_SSens + TAS_T + CERQ_Negative + IUS_comp
AASP_SAvo ~~ AASP_SSens
fit2 <- sem(model2, data = Dat_final.cep, estimator = "MLR", missing = "fiml", fixed.x = F)
summary(fit2, fit.measures = T, standardized=TRUE, modindices = T)
To compute post-hoc power using G*power 3 (in χ2 tests - Generic χ2 test) you need the following information 1) Non-centrality parameter 2) a err prob and 3) Df. The a err prob = .05, the df from my model above is 9, however, I am unsure which statistic refers to the non-centrality parameter?
I know that the non-centrality parameter = normal theory weighted least squares χ2 - df of your model. Does this mean that I have to run a model with the WLS estimator to get the normal theory weighted least squares χ2 to calculate power in G*power or is there something I am missing from my output above?
Also any alternative methods for calculating post-hoc power are welcome!