Audition is a kind of group decision-making problem, and its speciality is that there are often frauds. This paper
proposes a grey group decision-making model which can discriminate and reject the invalid decision value. The operator
of utility transform is applied to standardized transformation of the decision value, and a model is proposed to discriminate
the invalid decision value considering the decision maker’s preference information on indexes. Then the paper unbiases
the valid decision value, and applies the grey incidence model to evaluation. Finally, an example shows the feasibility and
effectiveness of the method.