Different multiattribute decision making (MADM) methods often produce inconsistent ranking outcomes for the same problem. In group decision settings, individual ranking outcomes made by individual decision makers are often inconsistent with the group ranking outcome. To address the inconsistency problem of ranking outcomes, this paper develops a new validation approach for selecting the most valid ranking outcome among all feasible outcomes. Based on four normalization procedures and three aggregation procedures, nine MADM methods are developed to solve the general group MADM problem that requires cardinal ranking of the decision alternatives. The validation approach selects the group ranking outcome of an MADM method which has the highest consistency degree with its corresponding individual ranking outcomes. A scholarship student selection problem is used to illustrate how the approach works. The approach is applicable to large-scale multiattribute group decision problems where inconsistent ranking outcomes often exist between different MADM methods and between different decision makers.