An action research project involving 25 master's supervisors, from health and education disciplines, sought to enhance their understanding of dissertation supervision. Recognising that they were sometimes slightly unsure about their role, they sought to identify issues that contributed to this circumstance, and to develop supervisor preparation materials to support future colleagues. During interviews and collaborative workshops, colleagues shared their experiences and reflected with one another on the nature of supervision. Through this process, they constructed a model that conceptualises how they practice. The core element is an ongoing assessment of a student's readiness, motivation and individual situation. In response to this assessment, supervisors balance three functions: Facilitating, Nurturing and Maintaining Standards. Facilitating encourages student growth through challenge or stimulation. Nurturing involves the provision of support and reassurance within a safe space in which this growth can occur. Maintaining standards ensures that academic and professional rigour are preserved.