Résumé
This chapter relies on a panel at INDRUM 1 in Montpellier (France) that takes a look at the interaction between researchers in mathematics and researchers in mathematics education (or in didactics of mathematics). In three case studies from Australia, United States and Mexico the nature and extent of different types of collaboration is discussed. The cases show the diversity of interactions, depending on not only the country and historical period, but also the educational level considered and the institutional context. In the conclusion benefits and pitfalls of established relationships are highlighted. Last but not least, directions that seem important to strengthen are pointed out.