多级计分的CD-CAT曝光控制方法

相对于0-1计分,多级计分考察的认知能力水平更高,能够提供更丰富的诊断信息,同教学实践更相符,而现有研究中鲜有基于多级计分的CD-CAT.该文提出了5种新的曝光控制的选题策略,分别是BSCDI_A、BSCTTID_A、BSCDI_D、BSCTTID_D和RP_PWCDI,将这5种方法同已有的PWKL和RP_PWKL进行比较,并尝试将这7种选题策略从0-1计分拓展到多级计分.研究结果表明:不管是0-1计分还是多级计分,采用统一量纲后的综合指标进行评价时RP_PWCDI(β=0.5)表现最好,题库使用均匀性各

The Exposure Control Methods of Polytomous CD-CAT

Many CD-CAT selection strategies focused on improving the classification correct rate,and ignoring the exposure rate.Most of them has high exposure rate,poor uniformity of item bank,and items drift.It spends more manpower and finacial resources on constructing item bank.So reasonable and effective exposure control methods are needed to improve item bank utilization for CD-CAT.In order to improve item bank uitilization,five exposure control methods are presented,they are binary searching algorithm and stratification with ascending Cognitive Diagnosis Index(BSCDI_A),binary searching algorithm and stratification with descending Cognitive Diagnosis Index(BSCDI_D),binary searching algorithm and stratification with ascending CTT item discrimination(BSCTTID_A),binary searching algorithm and stratification with descending CTT item discrimination(BSCTTID_D),combing RP with PWCDI(RP_PWCDI).Two simulation experiments were made to observe the five exposure control methods under dichotomous and polytomous models respectively.The results showed that under dichotomous model,the maximum exposure rate of the five methods was under 20%,the testing overlap rate was under 7%,BSCDI_A、BSCDI_D、BSCTTID_A、BSCTTID_D had the similar PCCR and item bank utilization.Under polytomous model,the PCCR of BSCDI_A、BSCDI_D、BSCTTID_A、BSCTTID_D was a little increased,and almost the same with RP_PWKL and RP_PWCDI.BSCDI_D and BSCTTID_D were a little poorer than BSCDI_A and BSCTTID_A on item bank utilization.