ABSTRACT
To some extent one can think of the study of countable models as being a special case of a Polish group action — since the infinite symmetric group, consisting of all permutations of the natural numbers, is a Polish group whose
action on countable models gives rise to the isomorphism relation as its orbit equivalence relation. In these talks I will try to emphasize the connections between recent work on Polish groups and some basic concepts one might see in a first course in logic or model theory.
