Hi. Can anyone point me to any module in R which implements "Little's Chi Square test" for MCAR. The problem is that i have around 60 behavioural variables on a 6 point categorical scale which i need to test for MCAR and MAR. What i can make out from preliminary analysis is that moderate (0.30 to 0.60) correlations may be present in several variable pairs leading me to suspect that the data may not be MCAR or MAR. However i need some more "concrete" proof. Any help - onlist or offlist - would be greatly appreciated. Thanks in Advance Rohit Vishal Kumar Ph.D. Student (Calcutta) India
Little's Chi Square test for MCAR?
3 messages · Rohit Vishal Kumar, Dimitris Rizopoulos, Frederico Zanqueta Poleto
This depends on the analysis you want to do; Maximum Likelihood will give you unbiased results even under MAR. In this case the more relevant question is whether the missing data mechanism is MNAR, in which case ML might give you biased results. Unfortunately you cannot test MNAR without making, some times very strong, assumptions. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://www.med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Rohit Vishal Kumar" <rohitvk at vsnl.com> To: <r-help at stat.math.ethz.ch> Sent: Monday, November 14, 2005 5:40 PM Subject: [R] Little's Chi Square test for MCAR?
Hi. Can anyone point me to any module in R which implements "Little's Chi Square test" for MCAR. The problem is that i have around 60 behavioural variables on a 6 point categorical scale which i need to test for MCAR and MAR. What i can make out from preliminary analysis is that moderate (0.30 to 0.60) correlations may be present in several variable pairs leading me to suspect that the data may not be MCAR or MAR. However i need some more "concrete" proof. Any help - onlist or offlist - would be greatly appreciated. Thanks in Advance Rohit Vishal Kumar Ph.D. Student (Calcutta) India
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