For nonnormal response distributions in generalized linear models, the distribution of the Pearson residuals is often skewed. Anscombe proposed a residual using a function A(y) in place of y in the residual derivation (Anscombe 1953, McCullagh and Nelder 1989). The function A(y) is chosen to make the distribution of A(y) as normal as possible and is given by
For a binomial distribution with mi trials in the ith observation, the Anscombe residual is defined as
For other distributions, the Anscombe residual is defined as
For the response distributions used in the fit analysis, Anscombe residuals are
The standardized Anscombe residuals are stored in variables named RAS_yname and the studentized Anscombe residuals are stored in variables named RAT_yname for each response variable, where yname is the response variable name.