FACES OF MATHEMATICS

Valerie Isham is a Professor in the Department of Statistical Science at University College London. Her research in applied probability involves the development and application of stochastic models. Her theoretical work contributes to the toolbox of tractable models available to an applied probabilist, and she is involved in interdisciplinary projects that apply such models to the physical and medical sciences.

"I use probability, or probability models, to represent the real world in some way. So I spend a lot of my time exploring models per se: thinking about assumptions that might be appropriate to a range of situations, and seeing what the consequences of those assumptions are.

"In a particular application, the essence is to determine what factors have most influence on the behaviour of the process, and to get rid of all the extraneous things, especially if you're doing stochastic modelling, where you have the opportunity to put in all the minor sources of variation through stochastic noise. So you're really trying to model processes in terms of the important things that drive their overall behaviour, and to strip out the rest. But finding out what those things are, and how to model them, is quite a challenge.

"I really do enjoy doing things that are useful, and where I think mathematics has a real role to play. But it is also a question of learning and understanding. That's what really drives me - learning new things."