This chapter maps the three concepts named in its title. It argues that there is reason to try to locate informal logic, critical thinking and argumentation studies in relation to one another. In general, such mapping of related concepts shares the feature of normative lexicography that it is quasi-normative, quasi-empirical. The aim is to suggest how the concepts in question ought to be seen to relate to one another, but any normative proposals should also be in touch with actual usage. The chapter first describes argument management as one way of understanding informal logic. There follows an account of the logical heart of argumentation, which identifies another way of understanding informal logic. Then critical thinking is related to those possible mappings of informal logic.