Working with groups unfamiliar with system dynamics, modelers need a quick way to introduce the iconography of the approach and some of its framing assumptions. In the early exploratory days of group model building interventions at the University at Albany, we settled on the use of sequences of tiny models for this purpose, which we call “concept” models. The intent is to begin with a sequence of simulatable pictures so simple and self-explanatory, in the domain and language of the group’s problem, that the group is quickly and naturally drawn into the system dynamics approach. Previous papers have sketched in passing the notion of concept models as we have used them. Here we provide a number of illustrative examples and describe in detail the ways we use these little models, the assumptions behind them, some design principles that have matured over time as our experience has grown, and a discussion of possible problems with the approach.