ESTIMATING PARAMETERS IN NONLINEAR RATE-EQUATIONS

Reaction rate equations with coefficients that have an Arrhenius dependence on temperature require nonlinear procedures to obtain parameter estimates. Estimates are important, but of equal importance are their measures of plausibility. The simplest measures, in the form (estimate +/- limits), are based on linear approximations, which can be, and often are, highly misleading. But there is no need to use approximations because modern statistical profiling techniques can produce accurate intervals very efficiently. Profiling also provides valuable insight into the estimation situation by revealing how models can be simplified. Strategies are given for model reformulation and parameter transformation to produce models with well-behaved estimates.