Dietterich (1998) reviews five statistical tests and proposes the 5 x 2 cv
t test for determining whether there is a significant difference between th
e error rates of two classifiers. In our experiments, we noticed that the 5
x 2 cv t test result may vary depending on factors that should not affect
the test, and we propose a variant, the combined 5 x 2 cv F test, that comb
ines multiple statistics to get a more robust test. Simulation results show
that this combined version of the test has lower type I error and higher p
ower than 5 x 2 cv proper.