Re: st: calculating alphas with imputed data

[Justina Kamiel Grayman <justina.grayman@nyu.edu>]

Yes, I did check the mi estimate's supported commands and calculating
the cronbach's alpha (scale reliability) is not supported. i also
tried using mi estimate, cmdok: alpha, but it returned an error. below
is my syntax and the error message

. mi estimate, cmdok: alpha bs3c1 bs3c3 bs3c4 bs3c6 bs3c7 bs3c8 bs3c9
if knowlmle<82.6
matrix e(b) is not set
matrix e(V) is not set
r(301);


On Thu, Jun 9, 2011 at 3:27 AM, daniel klein
<klein.daniel.81@googlemail.com> wrote:
> Justina,
>
> I think you need to be a little bit more specific about what exactly
> you mean by "alpha"? Most times I see "alpha" it is used to denote the
> type I error in NHST. Since this quantity cannot be estimated, I
> assume you mean something different. However, people use "alpha" to
> denote the constant in a regression as in y = alpha + betaX +e. It is
> also known in the context of reliability as Cronbach's alpha and there
> are probably a lot of other situations where this greek letter is
> used. Without knowing what it is you want to estimate it is not
> possible to tell you how you would do it with multiply imputed data.
>
> I assume you know the command to estimate "alpha" in non-imputed
> datasets. I further assume you did check the supported -mi estimate-
> estimation commands (-help mi estimate-) and did not find the command
> you are looking for.
>
> You may try to use -mi estimate ,cmdok : command- , where comand is
> the command you would use to estimate "alpha" in non-imputed datasets.
>
> If this does not work a good place to start might be here :
> http://www.stata.com/support/faqs/stat/mi_combine.html
>
> Combining point-estimates is relatively straight forward. Simply run
> the estimation on each dataset and save the results. The mean of those
> results is the MI-Estimator.
>
> Best
> Daniel
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>



-- 
Justina Kamiel Grayman
Doctoral Student, Psychology & Social Intervention
New York University

*
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