This article presents elements from the research journey pursued by the author in the area of interdisciplinarity in education, and more specifically in elementary education, which he has been studying for 30 years. The text begins by presenting the reasons that led to undertaking doctoral studies on this issue. It then addresses the foundations of the conceptual frame of reference used by the author in performing research studies. The article then examines three results that emerge from this research: a conceptual clarification of the notion of interdisciplinarity with respect to curricula and professional training; certain empirical findings on the conception and practice of interdisciplinarity among elementary school teachers; and the existence of three interpretive logics of interdisciplinarity associated with three distinct cultures--English-speaking American, French-speaking European, and Portuguese-speaking Latin American. To conclude, the article proposes a definition of interdisciplinarity in schools based on the Francophone reality, along with three principles for promoting an integrative approach in teaching-learning relationships.