賦予獨立型試題一適當機率架構，在古典測驗理論的概念下，探討試題難度與鑑別度之計算公式，並以九十六學年度第二次國中基本學力測驗數學科試題為例說明;同時將獲得結果與傳統計算方式之結果相互比較，嘗試發掘兩者間的差異及其形成原因。 關鍵詞 : 獨立型試題、難度值、鑑別度值 / Modeling independent items with a probability structure , we investigate the computational formula of difficulty index and that of discrimination index. Data taken from the Mathematics Test Items of the Second Basic Competence Test for Junior High School Students in 2007 are used for empirical verification and the result is compared with that obtained by the traditional method. Discrepancies between these two methods are also discussed in this study. keyword: independent items, difficulty index, discrimination index