Statistical model discrimination methods were developed to efficiently and reliably choose the 'best' model for a system from a set of candidate models. Three promising model discrimination techniques are compared using three chemical engineering examples in this paper. The examples were studied via computer simulations in which experimental data were generated using a known model. The use of a computer simulation allowed factors such as error magnitude to be studied at different levels in repeat runs of the program. The results indicated the exact entropy method is the best method for use with non-nested nonlinear models, while the Buzzi-Ferraris and Forzatti (1983) method is best for use with nonlinear nested models.On a mis au point des methodes de Keywords: model discrimination, reaction kinetics, copolymerization. n science and engineering, it is often necessary to develop a I mechanistic model which explains the underlying phenomena governing a process. However, there are often several models which seem reasonable based on theory or existing data. The models are typically nonlinear in the parameters and may or may not be nested. The problem then, is how to determine whether one of the models provides a significantly better description of the process given the needs of the particular project and the available resources.Statistical model discrimination methods were designed specifically to address this problem. They describe how to design experiments which should provide the maximum amount of information on the strengths and weaknesses of competing models. They also describe how to rigorously analyze data to determine whether any of the models is significantly better than the others. Statistical model discrimination methods are typically sequential methods. This allows models to be compared and the value of further experimentation to be assessed after each experiment.Model discrimination methods that contain both design and analysis steps were introduced by Hunter and Reiner ( 1965), Roth ( 1965), Box and Hill ( I 967) and Reilly (1 970). However, they have not been extensively evaluated or systematically examined for their sensitivity to factors such as experimental error level or the quality of initial parameter estimates. For this reason, three of the most promising model discrimination methods were chosen for extensive comparison.The methods chosen were the Buzzi-Ferraris and Forzatti method (Buzzi-Ferraris and Forzatti, 1983;Buzzi-Ferraris et al., 1984, 1990, the exact entropy method (Reilly, 1970), and the Hsiang and Reilly (1971) method. These three ?Present address: Novacor Research and Technology Corporation, 2928-*Author to whom correspondence should be addressed. E-mail address:16th St. N.E., Calgary, AB T2E 7K7, Canada.penlidis@cape.uwaterloo.ca methods are described in the first section of this paper as part of an overview of model discrimination methods.The overview is followed by three examples. For each example, computer simulations were used to study the application of the three model discr...