Development of New Robust Optimal Score Function for the Weibull Distributed Error Term in Multilevel Models

Table 8

Bias and MSE of using Weibull, Wilcoxon, and REML methods when  = 6..

		REML		Weibull		Wilcoxon		Precision
N2	N1	Bias	MSE	Bias	MSE	Bias	MSE	Weib/REML	Weib/Wil	Wil/REML
5	5	2.167	1.533	0.214	0.286	2.38	2.004	1.087	1.096	1.092
	10	2.182	2.139	0.235	0.417	2.48	2.572	1.012	1.081	1.013
	20	2.182	3.514	0.22	0.627	2.458	4.117	1.072	1.065	1.1
	40	2.184	6.24	0.227	1.214	2.464	7.227	1.058	1.068	1.084
10	5	2.323	1.227	0.096	0.155	2.639	1.432	1.067	1.091	1.069
	10	2.324	1.591	0.111	0.179	2.625	1.853	1.065	1.096	1.062
	20	2.331	2.354	0.107	0.264	2.651	2.701	1.047	1.095	1.048
	40	2.304	3.857	0.101	0.44	2.622	4.427	1.048	1.098	1.046
20	5	2.369	1.021	0.044	0.104	2.667	1.165	1.041	1.098	1.039
	10	2.375	1.23	0.038	0.109	2.689	1.387	1.028	1.095	1.03
	20	2.38	1.638	0.058	0.145	2.69	1.842	1.025	1.095	1.027
	40	2.368	2.437	0.052	0.211	2.676	2.748	1.028	1.101	1.025
40	5	2.395	0.936	0.042	0.093	2.707	1.038	1.010	1.088	1.019
	10	2.417	1.058	0.044	0.094	2.729	1.169	1.015	1.087	1.016
	20	2.4	1.251	0.018	0.102	2.718	1.383	1.078	1.089	1.015
	40	2.382	1.643	0.02	0.147	2.693	1.827	1.097	1.096	1.015