This thesis examines the relationships between educational ideologies, the conceptualisation and enactment of practices, the factors and structures conditioning practices and academic subjectivities in nine course-sites within a hybrid graded/gradeless education (HGLE) context at a large research-intensive public university in Singapore. The study adopts a practice-based ethnographic approach and draws rich, varied data from participant observations, dialogic interviews, focus group discussions, artistic representations, and artefacts. Social practice theory (SPT) is applied within the research, composed of Schatzkiā€™s site ontology and Trowlerā€™s analytical construct of Teaching and Learning Regimes (TLR). The study investigates how the site-based social practices are constituted and conditioned in actuality through Sedlačkoā€™s four-part methodology. The study has established six overarching findings within a HGLE context: 1) the partial approach to gradelessness did not demand a significant change in the choice of practices but necessitated a change in conceptualisation and enactment of practices; 2) workgroup communities, structures and interactions impact the conceptualisation and enactment of practices but this impact is moderated by an individualā€™s agentic and ideological positionings; 3) individual agency and ideological positionings play a key role in how practices are enacted; 4) practices are enmeshed with each course-siteā€™s practice architectures, and thus ā€˜sayings, doings, and relatingsā€™ of a practice draw on the cultural-discursive, material, and social arrangements that exist within or brought into the course site to make a practice possible; 5) practices are interconnected and inter-related, and so learning in and across practices occurs; 6) no definitive validated approach to effective practice exist and are generally determined by significant moments of TLR that operate within specific contexts. A model mapping tool is developed to capture the ecologies of practicesā€”the intended, experienced, and enacted practicesā€”alongside the significant TLR moments. The model is aimed at informing and supporting reflexive teaching and academic development.