We propose total scattering experiments on samples of (1-x)BaTiO3-xBiYbO3 perovskites with x = 0, 0.04, 0.08 and 0.15 to resolve issues over the local structure and degree of clustering of the dopant system. The simultaneous incorporation of Bi3+ and Yb3+ into the BaTiO3 lattice leads to a continuous reduction in tetragonality based on powder X-ray diffraction data and disappearance of long-range ferroelectric polarisation as indicated by Raman spectroscopy. However, the Raman spectra for x > 0.06 provide strong evidence for the occurrence of short-range deformations and local non-cubic structure and this leads to dielectric behaviour that is different than expected for a perovskite with an average crystal symmetry described by the cubic centrosymmetric Pm-3m space group. Analysis of total scattering data will resolve how the local structure is leading to the dielectric behaviour.