*Six Questions with: Professor Rosemary Bailey*

Rosemary Bailey is a Professor of Statistics at Queen Mary, University of London and was an organiser of the Design and Analysis of Experiments programme in 2011 and an organiser of the Design of Experiments short programme during 2008.

**When did you become first interested in mathematics and what keeps your interest fresh?**

When I was learning to count, before I went to school, it suddenly occurred to me that the whole numbers go on FOR EVER! I thought that this was amazing. At school, I enjoyed lots of subjects, and I applied to university for maths and for some other subjects. I remember my interview at Nottingham: one of the people said to me "Do your degree in mathematics first. Then you can pick up the other subjects later." So I did my undergraduate degree in mathematics, and by then was completely hooked (which may have been the intention of that interviewer).

I find it hard to understand the final part of this question. There are always so many new fascinating things in mathematics. Maybe it is pertinent that so many of my friends are mathematicians. As a doctoral student, I was lucky to be part of a large, active supportive group. I talk maths to my friends. If I am stuck myself, my brain can be fired again by their enthusiasm in explaining their own work to me.

**Could you tell us a little about your career path so far and what your current research involves? **

When I applied to do a DPhil in pure mathematics, my potential supervisor warned me that there were not enough university posts for all people doing doctorates in pure mathematics, so I should undertake it only if I was interested in the research for its own sake. I was, so I did. But he was right, and there were a tough few years before I got a permanent job.

The decisive step was taking up a post-doctoral position in Edinburgh to use group theory in problems in the (statistical) design of experiments. I followed this with ten years at Rothamsted Experimental Station, working as a statistician in real agricultural research, then came back to academia in mathematics departments in the University of London.

My current research is a mixture. Some of it is general theory of the design of experiments. Some of it is driven by particular collaborations with biologists or other experimenters. Some of it is completely pure mathematics, either combinatorics or algebra.

**What achievements are you most proud of? **

This is a tough question, because it involves looking back rather than forwards. But here are some:

(a) Being allowed the privilege of running two programmes at the Newton Instiute.

(b) Publishing (jointly with 3 co-authors) a paper on generalized wreath products of permuation groups that is apparently the purest of pure mathematics but which solved a question posed by statisticians twenty years earlier. (c) As a result of being on the Royal Statistical Society's working party on First-in-Human experiments, using my knowledge and experience from agricultural experiments to devise designs for first-in-human experiments which respect all the current safety restrictions and yet reduce variance by a factor of three without increasing the number of participants.

(d) Discovering, during these 5 months at INI in 2011, that two papers of mine published in the 1980s, on rather different topics, which I had thought that no one had ever read, are now being cited as foundation papers in those two areas.

**How do you achieve a balance between your work and homelife?**

I find it hard to answer this. Being a mathematician is central to who I am. My mathematical brain does not turn off when I walk in through my front door. I go for long walks at the weekend. You might consider this to be "homelife". I certainly do it for pleasure, but I *also* know that the key idea for a proof may pop into my brain at the end of such a walk.

But there are other aspects of worklife, such as administration, dealing with management, and answering questions from undergraduates. I keep these at bay by having a strict rule that I have no access to email at home or on holiday.

**What advice would you offer to young women who are just starting their careers in the mathematical sciences? **

I don't understand this question. I was lucky enough that no one called me a "woman mathematician" or said that "girls don't do maths" until I was too far set on the path to be turned back. If you make a special box for "women in mathematics" you are inviting the idea that they are not proper mathematicians. That is enough to put anybody off.

Let me rephrase the question: *What advice would you offer to people who are just starting their careers in the mathematical sciences?

I would say: if you are not utterly driven to find out new mathematics, go away and do something else. If you are, be stubborn, keep at it, don't be too picky about the location of your first job, be sure to go to conferences in your chosen part of mathematics, don't be put off when your papers are rejected.

**Has your visit to the Newton Institute been fruitful?**

Oh yes! I learnt lots of new things in the workshops, made major improvements to two pieces of joint work that were supposedly just being "finished off" here, and started lots of new pieces of joint work with a variety of different participants.