If design used to be a matter of physical form, its subject the material object, it now increasingly seems to be about the user and her experiences. A central problem with this development is the confusion between what we are designing and who is going to use it—the shift towards user design. Trying to optimise fit on basis of knowledge about use and users, we risk trapping people in a situation where the use of our designs has been over-determined and where there is not enough space left to act and improvise.