Simple statistical agglomeration models can provide a universal link between the local structure and the glass transition temperature in network glasses. We first stress the physical features of the models and the hypothesis made, and then show how to define the glass transition temperature. The models are applied to various types of binary, ternary and multicomponent chalcogenide glass networks and the predictions compared to experimental data.

11 pages, Revtex, 5 EPS figures, Proceedins of the Cargese CNRS school "Physics of glasses: structure and dynamics", Cargese May 1999