# Criterions

Dr. Bean, who is unsatisfactory which the four decision criteria for decision making under strict uncertainty (Wald's maximin, Hurwicz's maximax, Savage's minimax,Laplace's) proposes the following Minimum Mean Regret Criterion: Choose an action $a_k$ such that its mean regret $\frac{(\sum_{j=1}^{n}r_{kj})}{n}$ is as small as possible, i.e.
choose $a_k$ such that $\frac{1}{n} \sum_{j=1}^{n}r_{kj}$ $=$ $min_{1\le i \le m} \frac{1}{n} \sum_{j=1}^{n}r_{kj}$
where $r_{ij}$ denotes the regret of consequences $v_{ij}$.