Problem Reformulation and Search
Ian Gent, Patrick Prosser, and Barbara Smith are investigating what happens to search effort when we change the representation of a problem. We will study the car sequencing problem, vehicle routing, and flexible job shop. More details on this work can be found at the project web-site.
 

Constrainedness and search
Ian Gent, Pat Prosser and Toby Walsh are interested in the impact of the constrainedness of problems on search. They have proposed a formal definition of constrainedness, and studied its value in NP-complete problems, as well as lesser and higher complexity classes (like P and PSPACE). See the Kappa pages for more information.
 

Non-binary constraints
Peter van Beek, Kostas Stergiou, Toby Walsh and Ian Gent have been comparing non-binary and binary representations of constraint satisfaction problems. One area of interest has been binary encodings of non-binary problems. Another has been non-binary constraints (like the all-different constraint) which can be decomposed into binary constraints without the need for additional variables.
 

Representation and Reformulation
Barbara Smith, Pat Prosser, Ian Gent and Toby Walsh are interested in the representation and reformulation of constraint satisfaction problems. One area of particular interest is reformulating between problem classes (eg vehicle routing as job shop scheduling). Another area of interest is the choice of an initial representation (binary v non-binary, auxiliary variables, implied constraints, ....). 
 

Symmetry
Ian Gent and Barbara Smith are investigating how we can remove symmetry from constraint satisfaction problems.
 

Planning and Scheduling
We are a node! With our ongoing interest in  planning and scheduling, we have joined  PLANET, the EU network of excellence in planning and scheduling.