Abstract
This paper describes the authors' work on the calibration of a distribution model for SELNEC transportation study. N form it is similar to the standard interaction model, but modifications have been introduced to allow a central role o be given to car ownership. The derivation of the model long the lines proposed by Wilson is outlined, and interpretations are offered for its various components. Finally the two techniques that have been used for calibration are described, and the way in which these have been influenced a knowledge of the underlying theory is explained.