RL30 Restricted and Unrestricted Models in the Domain of Mixed Models
*Jennifer Smith, Geron Corporation Keywords: There has been controversy about whether the restricted or unrestricted model is more appropriate but very few people are aware of the implications of this choice. SAS implements the unrestricted model whereas many textbooks describe the restricted model and do not even discuss the unrestricted model. There are a few people with strong opinions on either side and I think it’s an issue that people should be aware of and discuss more openly. The implications for this choice are huge. Consider the textbook case of a mixed model analysis of variance with 1 fixed factor and 1 random factor. The Expected Mean Squares would suggest that the appropriate error term for the fixed factor is the interaction term whereas the appropriate error term for the random factor is the error mean squares. In contrast, the unrestricted model results in Expected Mean Squares that suggest the interaction term should be the denominator for both.
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Key Dates
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April 30 - May 22, 2013
Invited Abstract Submission Open -
June 4, 2013
Online Registration Opens -
August 9 - August 23, 2013
Invited Abstract Editing -
August 23, 2013
Short Course materials due from Instructors -
August 26, 2013
Housing Deadline -
September 9, 2013
Cancellation Deadline and Registration Closes @ 11:59 pm EDT -
September 16 - September 18, 2013
Marriott Wardman Park, Washington, DC