The ability to discriminate the most probable reaction mechanism of a solid-state reaction is analysed and discussed. It is shown that the analysis of a single CRTA experiment (like any other single, conventional, thermal analysis experiment) is not sufficient absolutely to select the reaction mechanism, because several of them (three in the case of dolomite thermolysis) give an excellent fit with the CRTA curve. Fortunately, fully independent information is provided by the CRTA "rate-jump" method, from which a truly model-free activation energy is derived and which still keeps under control (like any CRTA experiment can do) the heat and gas transport processes (which is not the case with conventional TG). Among the three mechanisms selected, only one (with no possible doubt) is consistent with the "rate-jump" activation energy (197.8 kJ mol-1) which clearly shows that the thermolysis of ground dolomite, under vacuum, follows a first-order F1 mechanism (random nucleation unimolecular decay law).