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From |
"Woolton Lee" <finished07@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Re: Factor analysis after multiple imputation in STATA |

Date |
Thu, 12 Jul 2007 20:58:24 -0400 |

Thanks for your reply. So it sounds as though you are saying that I can use the EM algorthm to run factor analysis in the presence of missing data. Is that correct? How might I go about implementing this approach? By the way, do you have any references I might use to get some background on this approach? Thank you for your help, Woolton On 7/12/07, Rodrigo A. Alfaro <raalfaroa@gmail.com> wrote:

/// It is not clear to me what you can get averaging the factor loading. For a reasonable number of factors, you could print out your output for each imputed-dataset and try to find if there is any pattern. For example, variable x1 has some load between 0.7 and 0.74... if you get x2 has loads between -0.2 and 0.8, then I would think more carefully about the imputation method. Alternative, you could try EM-algorithm to get the variance-covariance matrix under normality assumption. With that it would be clear how to obtain the associated factors (there will be just one). Good luck, R ----- Original Message ----- From: "Woolton Lee" <finished07@gmail.com> To: <statalist@hsphsun2.harvard.edu> Sent: Thursday, July 12, 2007 4:44 PM Subject: st: Factor analysis after multiple imputation in STATA >I am working with a dataset with many missing values across the > variables and have used multiple imputation via chained equations > (created by Patrick Royston) to generate 5 multiply imputed datasets > with the objective of running factor analysis to analyze the > relationships among the variables in the dataset. However, it seems > that MICOMBINE is only tailored for regression type procedures and is > not appropriate for application when implementing factor analysis > after multiple imputation. Is there a STATA command such as MICOMBINE > that can be used to obtain factor loadings from the multiply imputed > data or will I have to apply Rubin (1987) 's formula manually (via > MATA or programming) to obtain the factor loadings after running > factor analysis separately on each of the imputed datasets? > > As a side note, I think that Rubin (1987)'s formula applied to factor > analysis would simply be the mean of the of the factor loadings across > the imputed datasets (I have 5 imputed datasets) , but is this > correct, or should I be using a different formula for the factor > loadings across imputed datasets? > > I would greatly appreciate any assistance, > > Woolton > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

* * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Re: Factor analysis after multiple imputation in STATA***From:*"Rodrigo A. Alfaro" <raalfaroa@gmail.com>

**References**:**st: Factor analysis after multiple imputation in STATA***From:*"Woolton Lee" <finished07@gmail.com>

**st: Re: Factor analysis after multiple imputation in STATA***From:*"Rodrigo A. Alfaro" <raalfaroa@gmail.com>

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