We introduce a new type of randomized incremental algorithms. Contrary
to standard randomized incremental algorithms, these lazy randomized
incremental algorithms are suited for computing structures that have a
''nonlocal'' definition. In order to analyze these algorithms we gene
ralize some results on random sampling to such situations. We apply ou
r techniques to obtain efficient algorithms for the computation of sin
gle cells in arrangements of segments in the plane, single cells in ar
rangements of triangles in space, and zones in arrangements of hyperpl
anes.