If I am given a system, which I might have to describe using a generalized entropy, like the "q-deformed" Tsallis entropy, do I have to fit q from experiment or might I know it beforehand? How do I know the parameter q and/or how can I possibly obtain the degree of non-extensitivity via experiment? How can I measure the entropy of a part of the system, if the system is non-extensive?
http://en.wikipedia.org/wiki/Tsallis_entropy
Edit:
After some browsing I think the answer might be related to the fact, that for q-deformed entropy, the most probable distribution is not the Gaussian, but seems to be the q-deformed Gaussian:
http://en.wikipedia.org/wiki/Q-Gaussian
Then I played around a bit:
http://img835.imageshack.us/img835/5841/qgaussian.png
Maybe one applies such an entropy concept if one comes across a distribution of such type, but that's only a guess. And I don't see why one would/could conclude non-extensitivity from a distribution?!
