How does supervisor support shape PhD students' learning experience? Evidence from the Nature Careers 2025 Global PhD Survey.

Supervisory support is central to doctoral students' learning experiences, yet the relative importance of contact frequency and support quality remains unclear. Using publicly available data from 3,785 PhD students in 107 countries in the Nature Careers 2025 Global PhD Survey, this study examines how supervisory contact frequency, relationship quality, research guidance, career guidance, and career support are associated with overall PhD satisfaction. Ordinary least squares regression provides the baseline estimates, supplemented by ordered logit and binary logit models and alternative-outcome and extended-control checks. Contact frequency is positively associated with satisfaction in descriptive and reduced models, but its independent association becomes weak and unstable after support-quality dimensions are introduced. In contrast, supervisory relationship quality, research guidance, career guidance, and career support remain positively and consistently associated with satisfaction across model specifications. These dimensions are also associated with whether students perceive their doctoral experience as meeting their initial expectations. The findings indicate that the quality and developmental content of supervisory interaction matter more than contact time alone. By disaggregating supervisory support, this study contributes global evidence to doctoral education research and informs institutional efforts to strengthen supervision quality, feedback, and career development support.