Anelastic relaxation and internal friction data of a variety of amorphous materials was analyzed, starting from the assumption that the underlying mechanism is stress-induced ordering, the kinetics of which is fully comparable with that of chemical short-range ordering. Using the equations and numerical values of the parameters derived from the chemical ordering process, a consistent description of the data on stress-induced ordering of amorphous materials is presented. In particular, it is demonstrated that both chemical ordering and stress-induced ordering are governed by "diffusion defects". The decay of the concentration of diffusion defects with time is consistent with what was observed in earlier experiments on structural relaxation. The analysis also yields a distribution of relaxation times in stress-induced ordering, the physical background of which is as yet unclear.