Climate models and their component parameterizations do not perform equally well for all regions of the globe or for all climate regimes. These disparities in model performance will become increasingly important as demand grows for climate-change information on regional scales. This session solicits contributions that explore the generality of climate models and their components across varying locations and across varying scales of space and time. Both global and regional climate models as well as reanalyses and data assimilation systems that use such models are relevant to this session. Examples of appropriate contributions include but are not limited to comparisons of model performance in different regions of the globe; independent verification of reanalyses for different regions or climate regimes; conflicts between the need for model "tuning" versus the conceptual ideal of generality; performance of parameterizations across a range of spatial scales; and relative performance of physical parameterizations when applied to differing climate regimes. Contributions that compare model performance across several GEWEX Continental Scale Experiment (CSE) regions are especially encouraged.