We have shown that the adiabatic reactor method (A.R.M.) is useful to measure bulk polymerization kinetics. The choice of an adequate model is fundamental to represent the kinetics and for use in modeling and processing applications. The definitions of differential and integral errors have been introduced. It has been shown that these definitions lead to different objective functions and minimization problems. With an adequate model, we must be able to find a single set of parameters to minimize both errors simultaneously. We have shown that the n-th order and autocatalytic models are particular cases of a generalized phenomenological model. We continue to study this technique and to develop new forms of estimation. Dynamic models for complex situations which may include heat losses and intermediate species are now under development, and we expect to present them in a forthcoming publication.