PhD Milestones: asking the right questions (HDR Supervisor Flipped Seminar)

PhD milestones can be tough for the student.  They should be rigorous, precise and clarifying.  They should not be brutalizing, cruel and confusing. 

This flipped training session for PhD supervisors probes the type of questions that can be asked of students and the scenarios to avoid.  

What is a productive suite of questions for students and their development?