[R] omega vs. alpha explanation

[R. Michael Weylandt]

Your subject line also suggests you might consult with your local priest. ;-)

Cheers,
RMW

On Wed, Oct 10, 2012 at 2:51 PM, Bert Gunter <gunter.berton at gene.com> wrote:
> Advice:
>
> Do not post here. This does not appear to be an R question. Post to a
> statistics list like stats.stackexchange.com instead.
>
> -- Bert
>
> On Wed, Oct 10, 2012 at 6:42 AM, codec cat <v.codecat at gmail.com> wrote:
>> Dear all
>>
>> I wonder if someone can explain what is the main difference between omega
>> and alpha reliabilities?
>>
>> I understand an omega reliability is based on hierarchical factor model as
>> shown in this graph<http://rgm2.lab.nig.ac.jp/RGM_results/psych:omega.graph/omega.graph_002_big.png>,
>>  and
>> alpha uses average inter-item correlations.
>>
>> 1. What I don't understand is, in what condition, omega reliability
>> coefficient would be higher than alpha coefficient,  and vice versa?
>>
>> 2. Can I assume if the correlations between the subfactors and the
>> variables are higher, the omega coefficient would also be higher  (as shown
>> in the omega graph<http://rgm2.lab.nig.ac.jp/RGM_results/psych:omega.graph/omega.graph_002_big.png>
>> )?
>>
>> Any advice is appreciated!
>>
>> Thanks.
>>
>>         [[alternative HTML version deleted]]
>>
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>
>
>
> --
>
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
> Internal Contact Info:
> Phone: 467-7374
> Website:
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>
> ______________________________________________
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