Amelia November 2012

amelia@lists.gking.harvard.edu

4 participants
4 discussions

Question about Amelia II for Missing not at random (MNAR)

by Kamontip Srihaset

Dear All, I am Ph.D student at Chulalongkorn University in Thailand, I use your package to impute missing data assump MAR and MNAR. I don't have problem to impute under MAR, but I don't know how to impute MNAR. My MNAR data generate under IRT model(3-PL); n<-500 ## number of examinee I<-20 ## number of items num.imp<-5 ##number of imputations p.missing<-c(0.09, 0.01) #prob of missing theta<-sort(rnorm(n,0,1)) #ability a<-rnorm(I,0.5,0.1) #discrimination b<-rnorm(I,0,1) #difficulty c<-runif(I,0,0.25) #guess Only item 1-4 have missing data. If the response to each items was a 1 (correct), the probability of missing for each items was 1%. If the response was a 0 (incorrect), the probability of missing was 9%. Thus, the probability of missing each items was linked to the response of each items itself (an unknown characteristic in real missing data situations). Could you please tell me function or how to impute data under my situation. I'am looking forward your advice. Sincerely yours, Kamontip Srihaset

11 years, 5 months

Question about Amelia II for Missing not at random (MNAR)

by Kamontip Srihaset

11 years, 5 months

Amelia Error code: 32

by Esther Kimani

Hi, I am a new user of Amelia and have had all sort of problems. First I don't seem able to save the session correctly which have meant I have to reload the data from Stata again and again then add transformation. That's quite frustrating! How do I get to save the session with all the changes made? Then I have the error code: 32. Which states: The options for transformations are not mutually exclusive. One variable can only be assigned one transformation. You have the same variable designated for two transformations. I don't understand which variables it means since I transformed each variable once. Most of my variables are nominal and ordinal, one squared, a few log and continuous. I have 2163 observations, 202 variables. I appreciate any help in sorting this error. Thank you. Best, Esther ### UNIVERSITY OF CAPE TOWN This e-mail is subject to the UCT ICT policies and e-mail disclaimer published on our website at http://www.uct.ac.za/about/policies/emaildisclaimer/ or obtainable from +27 21 650 9111. This e-mail is intended only for the person(s) to whom it is addressed. If the e-mail has reached you in error, please notify the author. If you are not the intended recipient of the e-mail you may not use, disclose, copy, redirect or print the content. If this e-mail is not related to the business of UCT it is sent by the sender in the sender's individual capacity. ###

11 years, 5 months

Amelia Error code: 32

by Esther Kimani

11 years, 5 months

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Amelia November 2012