Interdisciplinary learning (IDL) features heavily within Scotland's Curriculum for Excellence and is promoted as a way to develop skills building and conceptual creativity in students, factors which are now seen as crucial for the twenty-first century education system (Khadri, 2014; Kolmos, 2016). Recent studies suggest, however, that although teachers welcome the idea of IDL in principle, there is a serious policy implementation gap (Harvie, 2018, Graham, 2019). While it is recognised that the structure as well as the culture of organisations can hinder policy enactment (Thorburn, 2017), this article focuses on the issue of conceptual clarity as a barrier to implementation and aims to address this by considering an epistemology and conceptual framework through which IDL can be better understood. Factors which promote IDL are explored along with examples of practice which match the conceptual model. A structure for planning IDL tasks is also suggested with the intention of opening discussion around this topic and providing teachers with practical ideas.