Table 4.

RMSE of all variables for four methods. The bottom line gives the overall RMSE for each method. For PCA, the RMSE calculation includes the correlations of the variables with themselves.

	PCA		WALS
	$\delta =0$	$\delta =0.16$	$\delta =0$	$\delta =0.07$
	$\mathbf{R}$	${\mathbf{R}}_{{}_a}$	$\mathbf{R}$	${\mathbf{R}}_{{}_a}$
Length	0.2725	0.2734	0.0380	0.0170
Left	0.1624	0.1172	0.0616	0.0440
Right	0.1661	0.1855	0.0608	0.0641
Bottom	0.0665	0.0986	0.0071	0.0109
Top	0.2084	0.1080	0.0355	0.0186
Diagonal	0.3352	0.2890	0.0826	0.0790
All	0.2192	0.1949	0.0533	0.0466