The interrelations between the correlation coefficients (=r) for an Arrhenius representation (linearity lnk vs. 1/T) of runs evaluated by the one-step strategy, and their locations in the mechanistic diagram (reaction type indexM vs. shape indexS) are studied, based on 3000 DTA and UV experiments and 850 theoretical curves for 40 reaction mechanisms. It turns out that files corresponding to the source points of first- or second-order, or to theA-region located between, reveal a reliable Arrhenius line; but for particular mechanisms, files attributable to regions rather “distant” from this center, may also behave so. Therefore, further studies must lead to powerfulr,S,M-based kinetic pattern recognition methods.