Mathias Frisch (Maryland) gives a talk at the MCMP Colloquium (26 June, 2014) titled "Model Tuning and Predictivism". Abstract: Many climate scientists maintain that evidence used in tuning or calibrating a climate model cannot be used to evaluate the model. By contrast, the philosophers Katie Steele and Charlotte Werndl have argued, appealing to Bayesian confirmation theory, that tuning is simply an instance of hypothesis testing. In this paper I argue against both views and for a weak predictivism: there are cases, model-tuning among them, in which predictive successes are more highly confirmatory than accommodation. I propose a Bayesian formulation of the predictivist thesis.