Knowledge of dose is a fundamental starting point in the evaluation of the toxicity of chemicals, not only for interspecies comparisons but also for designing experiments that elucidate mechanisms of action and that identify issues or research areas for further study. Using a mathematical dosimetry model for ozone, the paper mainly focuses on how models can be used to identify dosimetric research issues and lead to implementation of research projects that address them. Critical to these efforts are sensitivity analyses wherein model parameters are varied and effects on predicted dose are quantified. The use of models to identify research projects and issues reflects an application which may in the long-term be equally important as the more traditionally recognized function of predicting the dose of a chemical at target sites.