Hi, in a five factor EFA solution the uniqueness calculation seems a bit off, not sure why. Hand calc gives me a uniqueness of 0.66 for a promax rotated solution but the jamovi displayed value is 0.74. Hand calc of the unrotated solution is correct, so I'm not sure why rotated factor loadings don't add up to displayed uniqueness. Using jamovi 0.9.5.5.
David
ps omv attached
Uniqueness calculation in EFA
Uniqueness calculation in EFA
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Re: Uniqueness calculation in EFA
Hi David,
So by default we use "Minimal Residuals" as the factor extraction method (just like the R package "psych" that we use in the background). However, "factanal" uses maximum likelihood as the extraction method. If you change the extraction method to maximum likelihood, the uniqueness should be the same again.
Cheers,
Ravi
So by default we use "Minimal Residuals" as the factor extraction method (just like the R package "psych" that we use in the background). However, "factanal" uses maximum likelihood as the extraction method. If you change the extraction method to maximum likelihood, the uniqueness should be the same again.
Cheers,
Ravi
Re: Uniqueness calculation in EFA
Hi Ravi, maximum likelihood also gives 0.66 uniqueness for a five factor promax rotated solution (hand calc) - but the displayes uniqueness is 0.74 (jamovi 0.9.5.
Re: Uniqueness calculation in EFA
jamovi 0.9.5.8 ... not sure why the shades appeared!
Re: Uniqueness calculation in EFA
jmv syntax shows nFactors = 2 but five are extracted using parallel method...could this be something to do with it? See attached.
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Re: Uniqueness calculation in EFA
..answering my own question, NFactors = 2 or NFactors = 5 in jmv syntax doesn't change things...
Re: Uniqueness calculation in EFA
But it does match the R result you calculated using 'factanal' now right?
Re: Uniqueness calculation in EFA
Using factanal handcalc uniqueness = 0.66 but displayed = 0.74, just like in psych. Probably something happening that I don't understand...I had thought that rotated factor loading should still sum to same communality / uniqueness as unrotated?
Re: Uniqueness calculation in EFA
Further digging shows that with orthogonal rotation (varimax) factor loadings combine correctly to displayed uniqueness, but not for oblique rotation (promax). Extraction method doesn't seem to make a difference.
Re: Uniqueness calculation in EFA
aah, pattern vs structure matrix!! Sorry I'm a bit rusty on fa