See Kao, Zeng and Basten (1999) for more detailed information on the information criteria. We use
IC(k) = -2(log(L) - k c(n) / 2)
where L is the likelihood for a k-parameter model and log is the natural log function. The penalty function c(n) takes one of six forms:
Use the numbers above with the -S option to indicate which information criterion you want to use. If you use penalty functions 1 through 5 above, then you should also specify a threshold of 0.0 with the -L function. Penalty function 6 is equivalent to no penalty function and requires an experimentwise threshold value that might be obtained via a permutation test.