Abstract: A technique for estimating the best children (i.e. the next generation of individual chromosomes) for use by an online genetic analyzer (GA) is described. One embodiment provides a method for evaluation of a GA in a control system for controlling a plant. Individuals are evaluated using data for evaluation. The data for evaluation is categorized into subdomains of a larger evaluating domain. Data for evaluation is sorted into an evaluation domain wherein an evaluation value of each individual is replaced by a model of coefficients relative to a standard model. The standard model is used to calculate an evaluation value. The evaluation value can include a mean value and/or a distribution. Moreover, the mean value and distribution can be valid for an area including a periphery of the subdomain. The evaluation value can be calculated as a model obtained by using a least-squares method to find coefficients relative to coefficients of the standard model.