  Gauss' law of error is generalized in Tsallis statistics such as multifractal
systems, in which Tsallis entropy plays an essential role instead of Shannon
entropy. For the generalization, we apply the new multiplication operation
determined by the q-logarithm and the q-exponential functions to the definition
of the likelihood function in Gauss' law of error. The maximum likelihood
principle leads us to finding Tsallis distribution as nonextensively
generalization of Gaussian distribution.
