### The information content of a multistate distribution

#### D. M. Boulton, C.S.Wallace

#### Journal of Theoretical Biology, Vol.23, No.2, pp.269-278, May 1969

In the literature we find two different expressions in use for
finding the information content of a population whose members each
occupy one of a number of states. The information content of a
population is equal to the optimum length of a message which fully
describes its members, and the two forms, which are not equivalent,
differ in the amount of information which a receiver of the message need
know beforehand, in order to be able to decode it. We believe that
terms measuring this prior information should be added and show that
when this is done the resulting expressions are essentially equivalent.