Daniel posted on Monday, February 14, 2005 - 6:10 pm
Hi, Is use of bootstrap standard errors for calculating indirect effects better than WLSMV-derived stanadard errors when working with categorical outcomes? When I calculate indirect effects without bootstrap, I get significant indirect effects. However, when I bootstrap, I get non-significant effects.
I don't know. I think it would depend on many factors.
Daniel posted on Friday, February 18, 2005 - 3:53 pm
Linda, one of my indirect effects (a*b) in this mediation analysis is not significant. However, each individual path (path a and path b) from the exogenous variable to the slope factor is significant. Do you have any idea how I would report this finding? Essentially, the pieces are significant but not the whole indirect effect.
BMuthen posted on Friday, February 18, 2005 - 5:04 pm
This can happen. For example, if the a and b parameter estimates are positively correlated, this increases the standard error yielding non-significance.
What is the sample size in the analysis where the z was sig. and the percentile was not? We found this to occur rarely in simulation data with continuous variables. In most cases the significant z is a Type I error though. When sample size is 200+, the z is never signifcant if the percentile is not.
bmuthen posted on Saturday, February 26, 2005 - 11:55 pm
That typically says that your model is difficult to estimate for your data, so that for different subsets of the data the estimation does not converge properly. For instance, the sample size may be small or the model ill-fitting. You can send your files to support if you want guidance on that.