*Post by a***@gmail.com*I'm trying to do a factor analysis on a questionnaire with 63 questions. Andy Field's SPSS book says the determinant of the correlation matrix shouldn't be less than .00001. Mine is 5.125E-16, and that's after removing the 8 questions with the highest intercorrelations (R>.7). Any suggestions? Thank you in advance.

I never noticed that criterion anywhere, but my (many)

FAs were almost always performed on smaller sets of items,

any my items usually were Likert-type scale items. What do

you have as your questionnaire items, more specifically?

You do not have 10 or 20 times the number of cases as

your number of items. That's a frequent recommentation.

But that advice is based on items with not-large correlations,

where that large of an N is needed to get a robust structure

to emerge.

If you do have Likert-type items, correlations of

more than 0.70 would be extremely large, since that

is about the maximum they should yield from their

inherent reliability.

What does your attempt at FA give you? Reasonable

factors? Are the estimated communalities reasonable

estimates for the item reliabilities?

- In case of small N (which yours /might/ be), I have

done FA with fixed estimates of reliability for the diagonal.

Hope this help.

--

Rich Ulrich