Experimental determination of the nonextensive entropic parameter q

We show how to extract the $q$ parameter from experimental data, considering an inhomogeneous magnetic system composed by many Maxwell-Boltzmann homogeneous parts, which after integration over the whole system recover the Tsallis nonextensivity. Analyzing the cluster distribution of ${\mathrm{La}}_{0.7}{\mathrm{Sr}}_{0.3}\mathrm{Mn}{\mathrm{O}}_{3}$ manganite, obtained through scanning tunneling spectroscopy, we measure the $q$ parameter and predict the bulk magnetization with good accuracy. The connection between the Griffiths phase and nonextensivity is also considered. We conclude that the entropic parameter embodies information about the dynamics, the key role to describe complex systems.