 Specifically,
Note that formula_21 In general, for non-Boolean functions, the performance will not correspond directly to the probability that the functions agree, although it will have some relationship.Throughout an organism's life, it will only experience a limited number of environments, so its performance cannot be determined exactly.The "empirical performance" is defined by
formula_22
where formula_23 is a multiset of formula_24 independent selections from formula_19 according to formula_18.