雖然各類多評準決策評估方法日益受到學者的重視，但是在準則權重的估算上，一直為各評估方法所忽視；一般而言，多採取主觀判斷法決定準則間的重要程度，進而挑選替選方案的優先順序。然而，準則權重常具有影響評估結果的關鍵性能力，因此權重的分配至為重要。本研究整理歸納各類權重分配的方式，並探討其優缺點，以作為多評準決策分析的基石。 決定準則權重的方法主要可分為兩類：直接決定權重的方法與間接決定權重的方法。直接權重水定法是直接準則求算權重，其缺點在於有時優劣關係值較難以決定；間接權重決定方法是利用決策者對替選方案的選擇與排列，換算準則的權重，其缺點在於所求得的權重是決策者的偏好權重。 不論是採用何種評估方法，都會遭遇的困難是過多的準則數目。通常的處理方式是採取層級的結構，針對每個層級的準則加以計算其權重。此外，在某些情況下，規劃者應給予決策者一組以上的權重搭配，供決策者進行決策的參考。
The scholars and professor emphasize the importance of multiple criteria decision evaluation method gradually, but they often neglect to how to estimate the weight of criteria. The scholar decides the degree of importance between the different criteria by subjective approach first, and then deciding the priority of different substitutions. The researcher, Yang, takes a research on the different method for deciding the distribution of weight of criteria which is very important can influence the priority of substitutions. We can use direct weight making method and indirect weight making method to decide the weight. The weight is calculated from criteria directly in direct making method which is weak in deciding the superiority. We also can get the weight by ranking the substitutions with the indirect making method which is mislead by director's preference. No matter taking the direct or indirect making method, it is difficult to get the weight because of too many pieces of criteria. The solution is to make the pieces of criteria as hierarchy structure and decide the weight for every hierarchy. For better, the planner can provide the different weight for director's reference in making decision.
