Thermodynamics, as both thermochemistry and thermophysics, is fundamental and central to the science of matter and, in particular, of condensed materials. While extensive data resources for thermodynamic quantities do exist, none of the experimental, simulation, or theoretical studies can keep pace with the rate of synthesis of new materials or provide reliable data for hypothesized materials. Correlation methods can fill this gap. We describe a range of recently developed correlation methods that rely on volume to predict thermodynamic quantities. In parallel with these, thermodynamic difference rules, which describe how properties of materials (say, of a group of solvates) may be inferred from corresponding properties of materials that neighbor them in composition, have recently been reviewed.