甄别答案抄袭的K指数方法

K-Index for Detecting Answer Copying

目前,除考场监考等考务手段外,考试安全机构还通过对考生作答的异常一致性进行试后甄别,从而判定考生是否抄袭。判定考生抄袭有多种统计方法,K指数是美国ETS在多项选择题考试中使用的判定方法之一。本文介绍了K指数的原理、方法,对使用K指数的结果进行了讨论,并认为K指数保守地估计了对考生由于偶然因素导致作答一致的概率。

Besides test invigilation, test security office recently also pays on detecting unusual agreement between two examinees to detect answer after the test. Among many statistical methods, K -index is used in attention copying multiple choices test by ETS to detect answer copying. This paper introduce and approach of K - index, discusses its resuhs, and considers that K conservative approximation to the agreement probability .