We demonstrate and discuss the process of gaining information and show an example in which some specific way of gaining information about an object results in the Tsallis–and not the Shannon–form of entropy.

We present an overview of information theory approach (both in its extensive and nonextensive versions) applied to high-energy multiparticle production processes. It will be illustrated by analysis of single-particle distributions measured in proton–proton, proton–antiproton and nuclear...

Examples of joint probability distributions are studied in terms of Tsallis’ nonextensive statistics both for correlated and uncorrelated variables, in particular it is explicitely shown how correlations in the system can make Tsallis entropy additive and that the effective nonextensivity...

The application of information theory approach (both in its extensive and nonextensive versions) to high-energy multiparticle production processes is discussed and confronted with experimental data on e+e− annihilation processes, pp and p̄p scatterings and heavy ion collisions.