In statistics, the widely applicable information criterion (WAIC), also known as Watanabe–Akaike information criterion, is the generalized version of the Akaike information criterion (AIC) onto singular statistical models.[1]
Widely applicable Bayesian information criterion (WBIC) is the generalized version of Bayesian information criterion (BIC) onto singular statistical models.[2]
WBIC is the average log likelihood function over the posterior distribution with the inverse temperature > 1/log n where n is the sample size.
Both WAIC and WBIC can be numerically calculated without any information about a true distribution.