 By the Principle of Indifference of Laplace, equipossible alternatives may be accorded equal probabilities if nothing more is known about the underlying probability distribution.It is a matter of contention whether the concept of equipossibility, also called equispecificity (from equispecific), can truly be distinguished from the concept of equiprobability.In Bayesian inference, a widely used definition of equipossibility is "a transformation group which leaves invariant one's state of knowledge".