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

 From nicola.baldini2@unibo.it To statalist@hsphsun2.harvard.edu Subject Re: st: factor analysis - interpreting the results, inclusion of dp variable Date Tue, 14 Aug 2007 19:57:35 +0200

```Sorry for jumping in the discussion, but did you have a look at the correlation matrix before spending times on complicated tests, like those available through -coldiag2- and -collin-???
I obviously agree with Scott: don't include the dependent variable in the factor analysis. Also: which kind of variables do you have? While I used a factor analysis with constructs (e.g. perceptions on Likert scales), I would never use it with """real""" things (e.g. profits, patents, age, etc...), it is often too complicated to interpret the findings.
P.S. Just to be sure: when you said "i stored the 4 factors as new variables", did you mean that you saved the factor scores with post-estimation command -predict-, right?
Nicola

At 02.33 14/08/2007 -0400, "georg wernicke" wrote:
>hello stata list,
>
>i have a probably rather simple questions to which i cannot find good
>links in the net.
>
>i have quite a number of independent variables which have been
>identified as significant in the literature before (around 16). when i
>add all them in a regression, not one single variable is significant.
>i want to employ factor analysis to get a persimonious model.
>
>here are my questions:
> 1. do i include the dependent  variable in the equation? (fac
>dependent  independent1..... etc.)
>2. the analysis is retains 4 factors and gives me a factor loading
>table which i rotated. now what do i do with the rotated table? i
>stored the 4 factors as new variables..do i simply ass them in the
>regression equation or do i only run a regression with these factors
>now?
>3. or does the result of 4 retained factors tell me that my model
>should consist of 4 independent variables only?
>
>sorry, i know some of the questions are probably quite blunt...but
>still, i am lost on what to do with the results..
>
>thanks
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