The general solution of thermally stimulated processes is known to need the complex formulation of a nonlinear functional. Classical solutions can yet be found in special cases of particular exchange mechanisms and using approximations. The implicit correlation between thermally stimulated conductivity (TSC) and luminescence (TSL) is an important element in the qualitative determination of the mechanism involved. In this paper we propose a method for deducing such information from a log(TSC) -vs-log(TSL) parametric plot. This method is expected to apply even in the complex situation of overlapping or low-level peaks. Typical cases are emphasized and an experimental illustration of the technique is proposed for stannic oxide monocrystals. The conclusions are shown to be in very good agreement with the results obtained from classical measurements of luminescence and photoconductivity.