The most user-friendly way to compute the reliabilities is to apply the
sucro command
/RELIAB CORR.M,AFACT.M,MSN.M,2
where CORR.M is the correlation matrix, AFACT.M is the rotated factor
matrix, and MSN.M is the matrix of means, standard deviations and
number of observations. The last parameter controls the number of decimals
in the output (the default value is 2).
All parameters can be omitted, if default matrices are used.
The sucro also computes Cronbach's alpha for the sum of the items. However,
Cronbach's alpha is not recommended, since Tarkkonen's measure is better in
every circumstance, see Vehkalahti (2000).
The sucro computes the reliabilities of the factor images, the factor scores
and the unweighted sum of the items.
M = More information on reliability of measurement scales
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