The traditional academic pipeline has branched out significantly in recent years. The motivation of students pursuing higher degrees has also changed dramatically in response to wider socio-economic needs. Supervisors of PhD students are consequently faced with the need to adapt supervision practices to equip graduates with a broader suite of workplace competencies. However, PhD supervision is a practice located in the broader setting of a higher education system, conditioned by factors that change over time. In this paper we share the perspectives of a range of STEM supervisors from varying backgrounds on their conceptions of the purpose and goals of the PhD. Archer's Social Realist theoretical framework was used in a comparative analysis between groups and across themes. It also enabled a novel visualisation in the form of a heat map, illustrating the mechanisms shaping supervision practices, highlighting the strong interplay between student agency and the development of particular dispositions.