A series of titanium compounds have been studied by x-ray photoelectron spectroscopy within the Auger parameter formalism. Two different titanium Auger parameters are reported, both calculated from binding energies resulting from photoemission from Ti 2p 3=2 core-level states. Of the two values, one has been commonly used for titanium Auger parameter analysis and involves a valence-level Auger transition (L 3 M 2;3 M v ), whereas the other is based purely on core-level transitions (L 3 M 2;3 M 2;3 ). Both parameters correlate roughly with each other and with extra-atomic relaxation energies calculated from surrounding nearest-neighbor anion polarizabilities. However, the core-level-based Auger parameter shows significantly better correlation with predicted relaxation energy values, particularly when corrections are made for M 2;3 multiplet splittings in the analysis. The ability to model extra-atomic relaxation with polarization energies suggests that the ligand polarizabilities in titanium thin-film and powder samples may be estimated reliably from Auger parameter data despite the high degree of covalent character found in many of these compounds.