  The limitation of permutation tests is that they assume exchangeability. It
is shown that in generalized linear models one can construct permutation tests
from score statistics in particular cases. When under the null hypothesis the
observations are not exchangeable, a representation in terms of Cox-Snell
residuals allows to develop an approach based on an expected permutation
p-value (Eppv); this is applied to the logistic regression model. A small
simulation study and an illustration with real data are given.
