We use molecular-dynamics simulation to examine the order-disorder behavior in pure ferroelectric KNbO(3)and in KNbO3-KTaO3 ferroelectric-paraelectric solid solutions and superlattices. We find that the order-disorder behavior is remarkably robust and plays an important role in both the polarization rotation associated with switching of the perfect crystal and in the dynamical behavior of the solid solutions and superlattices. (c) 2005 Springer Science + Business Media, Inc.