Table 4: Dataset independence for gradient-based features, two datasets combined.

Classifier Trained on Tested onError versus avg. of own testsets
MNIST DIGITS USPS

IBk1 eucl. MNIST-DIGITS 3.58 7.41 9.87 1.80x
IBk1 eucl. MNIST-USPS 1.98 15.59 3.34 5.86x
IBk1 eucl. USPS-DIGITS 9.51 7.80 4.14 1.59x

SVM linear MNIST-DIGITS 3.43 4.79 11.01 2.68x
SVM linear MNIST-USPS 2.23 15.14 3.39 5.39x
SVM linear USPS-DIGITS 7.50 6.24 4.38 1.41x

SVM poly. MNIST-DIGITS 1.84 3.51 6.58 2.46x
SVM poly. MNIST-USPS 0.91 10.75 2.54 6.23x
SVM poly. USPS-DIGITS 5.94 4.45 2.94 1.61x

SVM RBF MNIST-DIGITS 1.88 3.51 6.98 2.59x
SVM RBF MNIST-USPS 1.00 11.53 2.44 6.70x
SVM RBF USPS-DIGITS 6.22 4.57 2.84 1.68x