[R] Control variables in mediation analysis

2013-03-21 Thread F.Doerwald
Hi everyone,I would like to test a mediation model, that has several control variables. More specifically, I would like to test the indirect effect with bootstrapping. However, all the packages I have found so far (e.g. MBESS) only allow testing a simple mediation model (One independent, one

Re: [R] Control variables in mediation analysis

2013-03-21 Thread Ista Zahn
Hi, Just about anything can be bootstrapped, that's one of the things that makes bootstrapping great! Use e.g., the boot package, and bootstrap the product of the coefficients. Alternatively the mediation package (http://cran.r-project.org/web/packages/mediation/index.html) might help, though

Re: [R] Control variables in mediation analysis

2013-03-21 Thread John Fox
Dear Ista and F.Doerwald, F.Doerwald could also fit a model using sem() in the sem package, and then use deltaMethod() in the car package to get the estimated value and standard error of any function of model coefficients that he or she chooses. Sorry, I didn't read the original posting. I

Re: [R] Control variables in mediation analysis

2013-03-21 Thread Bert Gunter
Well, yeah ... but it doesn't necessarily follow that the result converges to what you want. Bootstrapping extreme order statistics is an example. -- Bert On Thu, Mar 21, 2013 at 1:49 PM, Ista Zahn istaz...@gmail.com wrote: Hi, Just about anything can be bootstrapped, that's one of the