Abstract. The parameters of cooperative models are estimated in a boundederror context, i.e., all uncertain quantities are assumed to be bounded, with known bounds. In this context, guaranteed estimation is the characterization of the set of all parameter vectors that are consistent with the model and experimental data, given these bounds. Interval techniques provide an approximate but guaranteed enclosure of this set. No parameter vector consistent with the experimental data and model structure can be missed, so this approach bypasses the structural identifiability study required by the usual approaches based on local optimization of some cost function.