Integrating qualitative and quantitative methods for model validation and monitoring

The issue of monitoring a time-varying plant for qualitative (structural) changes in each model when the model´s equations are not known is addressed. Problems with multivariate continuous domains are examined, and an overview of qualitative physics and the problem of qualitative learning and monitoring is given. Qualitative models and the semantics of qualitative transitions are discussed. The learning and monitoring are discussed. Results of experiments with a system that learns how to select one of the models given access to quantitative variables characterizing the controlled plant are presented. The model selection system makes its decisions only when a qualitative change in the plant´s behavior takes place