Abstract
We study three kinetic models with constraint, namely the symmetrically constrained Ising chain, the asymmetrically constrained Ising chain, and the backgammon model. All these models show glassy behaviour and coarsening. We apply to them the Stillinger and Weber (SW) decomposition, and find that they share the same configurational entropy, despite their different non-equilibrium dynamics. We conclude therefore that the SW decomposition is not relevant for models of this type.