Experimental measurements have been carried out in previous efforts on the scattering of elastic waves from ellipsoidal and spherical cavities embedded in titanium on alloy by the diffusion bonding process. The scattering data have been compared with calculations from exact theory and those from the Born approximation. The results demonstrated that the new concept of sample fabrication by the diffusion bonding process is successful, and that the approximate scattering models developed to date are both useful and correct within acceptable limits for many applications. Efforts have been expended this year to provide a scheme and useful data base for the development of inversion techniques (i .e., deterministic, probabilistic, or adaptive schemes) from which quantitative properties of the scattering center can be rapidly extracted. The work has provided a preliminary definition of the minimum quantity and type of data acquisition needed for a "smart" NDE system.