19 August 2026

Photo: UHH/ Rahul Cecil

Dieter Horns and his PhD student Qixin Yu

You’ve been supervising doctoral students for many years. How long have you been doing this, and what has shaped you in the process?

I’ve been actively supervising students since I became a professor here in Hamburg in 2007. That’s almost 20 years now. Roughly speaking, I help about one to two doctoral students graduate each year—so somewhere between 20 and 30 in total as their primary advisor. What has shaped me in this role? To be honest, getting started was like jumping in at the deep end. No one is born a supervisor. And that realization to suddenly take responsibility for people’s careers, that weighed on me for a few years until I’d truly come to terms with it and knew what I was doing.

What would you say today: What makes a good supervisor?

That’s hard to boil down to a single point. But if I had to try: A good supervisor listens attentively and has a sense of what a doctoral student really needs. And that’s not always the same. Some need a lot of freedom, others need clear guidelines and direction. The approach has to adapt: to the person, to the situation. That sounds simple, but it isn’t.

Is there anything you would do differently in hindsight?

Yes, definitely. Co-supervision, for example. In our department, it often works like this: a second advisor is formally involved, but in practice does engage until the dissertation is on the table. That’s often a lost chance, because a second perspective during the process would be much more valuable than just at the end. As a community at Quantum Universe, we still have a lot of untapped potential that we’re unfortunately wasting right now. And the external conditions aren’t always right either: we act as if three years of funding are enough to complete a dissertation—yet the median in the physics department is over four years. That makes supervision unnecessarily difficult for everyone involved.

You mentioned that you‘ve been a supervisor for almost 20 years. What led you to participate in a supervision workshop recently?

I’m always looking for ways to improve. There had been other offerings for a while, but they were more geared toward beginners and didn’t really help me move forward. When I heard about the “Next Level Workshop for Experienced Supervisors”—which focuses less on theory and more on genuine exchange among experienced supervisors—that was exactly what I’d been looking for.

What made this workshop special?

The fact that we really got down to business. We had a homework assignment beforehand: to describe an anonymized case from our own experience. We then discussed these cases together in small groups. These included, for example, situations where a dissertation dragged on for five years and the student simply couldn’t bring it to a close. Or cases where doctoral students felt that the final grading hadn’t been transparently fair. These are real challenges you don’t learn about from a textbook. And the methods we were taught are based on psychological studies—the trainers didn’t just make them up themselves.

I was also particularly impressed by an unusual discussion exercise: One person presents their problem but then turns their back to the group while the others discuss it. You listen, but you completely step back from the conversation. It sounds strange, but it has a surprisingly clear effect: it makes the discussion more focused and honest.

What specifically will you apply to your next supervision?

Above all, the “alignment” tools—that is, those for aligning expectations early on. There are often gaps between what I expect as a mentor and what the students expect that aren’t immediately apparent. We were given specific checklists and discussion guides for this, which I plan to use right away when I start my next supervision. My new doctoral student is starting in September, so I’ll be approaching things this way from the very beginning.

What would you say to other supervisors who are considering whether to participate in a workshop like this?

Highly recommended! Especially for those who think they already know it all. But please take the time to carefully research which program is the right fit beforehand. The exchange with other experienced supervisors—that’s the heart of it. No trainer can truly replace that. We’ve all been through it, we’ve all made mistakes, and we can learn an incredible amount from one another. This kind of workshop provides the perfect setting for that.