  We derive a generalized deviation equation -- analogous to the well-known
geodesic deviation equation -- for test bodies in General Relativity. Our
result encompasses and generalizes previous extensions of the standard geodesic
deviation equation. We show how the standard as well as a generalized deviation
equation can be used to measure the curvature of spacetime by means of a set of
test bodies. In particular, we provide exact solutions for the curvature by
using the standard deviation equation as well as its next order generalization.
