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

From   SR Millis <>
Subject   Re: st: Re: Factor analysis after multiple imputation in STATA
Date   Tue, 17 Jul 2007 11:10:41 -0700 (PDT)

Full information maximum likelihood (FIML) uses only
the observed data. To over-simplify, FIML partitions
the cases into subsets with the same patterns of
missing observations. All available statistical
information is extracted from each subset and all
cases are retained in the analysis.

More formally, mean vectors and covariance matrices
are formed for cases that have the same pattern of
observed data. Once the mean vectors and covariance
matrices have been formed, the FIML approach of
Arbuckle (1996) uses the fact that for the i-th case,
the log-likelihood function can be expressed as:

log Li=Ci - 1/2log|Si| - 1/2(xi-mui)'S^-1(xi-mui)

and the log likelihood of the entire sample is the sum
of the individual log likelihoods.  The likelihood is
maximized in terms of the parameters of the model.

As a practical matter, FIML can be easily implemented
in multiple regression and factor analysis models to
handle missing data to that no cases are lost.

Scott Millis

--- wrote:

> Then the analysis would be only on the observed
> data? Or is there any hidden 
> imputation type of process going on? Thanks!

Scott R Millis, PhD, MEd, ABPP (CN,CL,RP), CStat
Professor & Director of Research
Dept of Physical Medicine & Rehabilitation
Wayne State University School of Medicine
261 Mack Blvd
Detroit, MI 48201

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