Book3 48页

胡老师~请问这两个方法最本质的区别是什么呢？通过做题我发现似乎意思是说，cost可以知道的就用install，cost不能知道的就用cost recovery，可是书上对于cost recovery的使用方法是说，cost不知道，或者收入收回不确定，那么如果遇到收入不确定，而cost知道的情况下，似乎也可以使用cost recovery阿？请老师指点一下~

这五种方法的分类标准是提供劳务是否完工，成本和收入能否确定，见下表总结。

Completion of Earnings                                            Assurance of Revenue     Method

Complete                                                                 Yes                 Sales basis

Complete                                                                 No                  Installment sales

Complete with contingencies                                     Yes                 Cost recovery

Complete with contingencies                                     No                  Cost recovery

Incomplete and costs can be estimated                     Yes                 Percentage of completion

Incomplete and costs can be estimated                     No                  Completed contract

Incomplete and costs can't be estimated                    Yes                 Completed contract

Incomplete and costs can't be estimated                    No                  Completed contract