One approach to constructivism is model-theoretic: to consider models, even in a classical meta-theory, of constructive theories. Two common kinds of models are topological and Kripke models. I will present these approaches to modeling in a way designed to appeal to classical mathematicians. These talks will include lots of examples of particular models, and will also bring out relations with other common techniques: forcing, symmetric sub-models, inner models, non-standard models, each other.