# Re: st: factor analysis - interpreting the results, inclusion of dp variable

 From "georg wernicke" To statalist@hsphsun2.harvard.edu Subject Re: st: factor analysis - interpreting the results, inclusion of dp variable Date Mon, 13 Aug 2007 18:44:35 +0100

```Dear SR Mills,

thank you very much for your help. It is most appreciated. I am just
going over the mentioned article, it seems as i have some
collinearity. i dropped 2 variables which are indicated as collinear
by the belsley threshold, the factortest immideately went up from 4 to
7 factors and will prob. improve once i have corrected for all
possibly collinear variables.

however, do i include the dependent variable in the factor equation?
(e.g. factor dependent independent1 independent2 etc..)

and what do i get from knowing that the factor analysis gives me lets
say 9 factors?

once again, thanxs for your help

george

On 8/13/07, SR Millis <srmillis@yahoo.com> wrote:
> Based on guidelines from Belsley et al. (pp.
> 112-113;2004) it does appear to me that you do have
> significant collinearity among some of your variables.
> Large variance-decomposition proportions (>.5)
> associated with each condition index (>30) identifies
> the offending variables.  I'd want to drop some of the
> variables causing the collinearity---and re-run the
> analysis--with the individual variables.
>
> SR Millis
>
> Belsley, D. A., Kuh, E., & Welsch, R. E. (2004).
> Regression diagnostics: Indentifying influential data
> and sources of collinearity. Hoboken, NJ: John Wiley &
> Sons.
>
> wrote:
>
> > Hello SR Millis,
> >
> > the highest condition index is 57.29. regarding the
> > variance
> > decomposition proportions, there are 6 above 0.5
> > when the condition
> > index is ~30. . seems a bit weird that the table
> > using coldiag2 gives
> > me 17 indexes even so i only have 16 variables.
> >
> > thanks again,
> >
> > george
> >
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```