Information of IRT Multilevel Item
项目反应理论框架下多级评分项目的信息函数

The objective was to give out calculate formula of multilevel item information function,and give some examples of multilevel item information.Results was: 1) at first discuss the sample sky of the test item by a example;2) give out the probability function and information function of multilevel item;3) discuss the application of multilevel item information function in practice by a few examples.