Greatest lower bound and other alternatives to Cronbach's alpha

[Paul Lokubal]

Hello everyone,

What are the stata commands for glb (greatest lower bound) for estimating internal consistency? I read it is a better estimator of internal consistency than Cronbach's alpha. However, I cannot find any Stata command or even clues on the internet.

Thank you,

Paul

[daniel klein]

As far as I remember, the glb (greatest lower bound) is often criticized to overestimate reliability. Also, I think there is more than one way to define the glb.

Anyway, as far as I know, Stata only provides the alpha command to estimate Cronbach's alpha (or: Guttman's lambda 3) coefficient. I have written guttmanl (last character is not the number 1 but a lowercase l [that is: not an uppercase I but L in lowercase]) a while ago; the command is available from the SSC and estimates Guttaman's lambda coefficients 1-6. The maximal lambda 4 coefficient is equivalent to one definition of the glb.