# How to compute multidimensional omega with R

I need to perform a computation of reliability of a 5-point Likert scale having 6 items. From a factor analysis I found that my scale is a multidimensional scale (3 factors), so I cannot use Cronbach's alpha to compute reliability. I have seen in several papers that it is possible to use the multidimensional extension of the McDonald's omega. Does the omega function in the psych package allow to do this?

Also, is there an R function to compute the Stratified alpha?

• It would help if you answered the questions I asked for your preceding question... (and please register your account so that you could vote and accept @Jeromy's earlier answer.) – chl Jun 10 '11 at 8:56
First yes it does, see http://www.personality-project.org/r/psych/help/omega.html and second there is a package sirt http://www.inside-r.org/packages/cran/sirt/docs/stratified.cronbach.alpha that you can use for stratified alpha.