If the size of a space is measured by counting the number of places availab
le for a particular activity, rather than by using an absolute measure such
as the square metre, then small people may find the world larger. Size mea
sured by number of places becomes a function of the size of the user, and t
he form of this function suggests that the everyday environment has a fract
al dimension, a single number which may be associated with architectural qu
alities. This measure was tested with an experiment based on children playi
ng hide and seek and was used to explain some illusions of perception of si
ze.