Re: [amelia] question about bootstrappping EM

There were some videos about imputation procedures on amelia at  http://psweb.sbs.ohio-state.edu/methods_videos/index.html. But it seems that the site has been reeearranged and I cannot find them anymore. Fortunately I recorded the entire political methodology series. I have now uploaded the imputation videos to a free storage service. Here is the link: http://www.sendspace.com/file/zpd323 I believe the link will work for a limited period of time and a restricted number of downloads. If you want and are not able to download from this source. mail me and I will upload again. What To Do About Missing Data in Political Science           Instructors:     Gary King James Honaker Anne Joseph Kenneth Scheve The videos are a basic intro to the method used in amelia and were as I recall created 1999 long before the gui version became available. regards/Shane --- On Thu, 6/5/08, tdavis7(a)emory.edu <tdavis7(a)emory.edu&gtu> wrote: From: tdavis7(a)emory.edu <tdavis7(a)emory.edu&gtu> Subject: [amelia] question about bootstrappping EM To: "amelia(a)lists.gking.harvard.edu" <amelia(a)lists.gking.harvard.edu&gtu> Date: Thursday, June 5, 2008, 6:25 PM Hello - My understanding of these methods is very basic, but I was hoping someone could offer some clarification on the specifics of the imputation procedure used in AMELIA II. I understand that in single regression imputation variances are often underestimated because the variable with missing data is a perfect linear function of the other variables used to impute it (correct?). However, I gather that AMELIA corrects for this in three ways: 1) First, by using an EM algorithm which adds a residual term to the variance 2) by adding a random component to reflect uncertainty in the missing data 3) using multiple imputed data sets to reflect this uncertainty as well. Is this correct or is this too basic an understanding? I would appreciate any help that could be offered. Thank you. - Amelia mailing list served by Harvard-MIT Data Center [Un]Subscribe/View Archive: http://lists.gking.harvard.edu/?info=amelia