From: Forstero on 7 Feb 2007 12:42 I am working with with a dataset that has categorical variables and some of these categorical variables has missing observations. Th eproblem I am having is imputing for these missing observations. Can anyone please help me with how to impute for categorical data? I know about the proc MI data step but it only seems to work for continous variables with two or more variables having missing observations. I will appreciate any help I can get on this subject. Thanks, Forster
From: Paige Miller on 7 Feb 2007 13:11 On Feb 7, 12:42 pm, "Forstero" <Forst...(a)gmail.com> wrote: > I am working with with a dataset that has categorical variables and > some of these categorical variables has missing observations. Th > eproblem I am having is imputing for these missing observations. Can > anyone please help me with how to impute for categorical data? > I know about the proc MI data step but it only seems to work for > continous variables with two or more variables having missing > observations. > I will appreciate any help I can get on this subject. > > Thanks, > > Forster The problem with imputing values is that all imputation that I am familiar with is set up to minimize (or optimize) some quantity. And this minimization can only be done with continuous variables. Now, I suppose you could define a "distance metric" among your categorical levels and then write your own imputation program to minimize the distance in this newly defined "distance metric", but I have never seen such a thing done. Good luck. -- Paige Miller paige.miller(a)kodak.com
From: tanwan on 7 Feb 2007 14:31 You might try IVEWARE software, available from the University of Michigan at http://www.isr.umich.edu/src/smp/ive/. It is free. It is callable in SAS (think of it as a big macro). You will need to install a small file on your PC. You will need to devote time to study the documentation. But after that, it becomes a cinch. And you should NOT run it in the SAS's Enhanced Editor. It will not work. But it can impute categorical variables.
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