Repeater Analysis for Combining Information from Different Assessments

• Activity Number: 300
• Type: Contributed
• Date/Time: Tuesday, August 5, 2014 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistical Education
• Author(s): Lili Yao*+ and Shelby Haberman
• Companies: Educational Testing Service and ETS
• Keywords: Augmentation ; repeaters ; adjustment

Abstract

How to examine the information from combined assessments is very important in educational statistics, for such information is often related to decisions. For example, American graduate schools usually receive both TOEFL iBT scores and GRE scores of foreign applicants for admission; however, little guidance has been given to combine information from these two assessments, even though the relationships between such sections as GRE Verbal and TOEFL iBT Reading are obvious. In this study, principles are provided to explore the extent to which different assessments complement one another and are distinguishable. Augmentation approaches (Wainer et al., 2001; Haberman, 2008) developed for individual tests are applied to provide an accurate evaluation of combined assessments. To measure the unavailable internal reliability, data on repeaters (Siegert & Guo, 2009), are assessed. The minimum discriminant information adjustment techniques (Haberman, 1984) are applied to treat the effect of selection bias. Analysis suggests that information from the GRE and TOEFL iBT assessments is complementary but not redundant, indicating that the two tests measure related but somewhat different constructs.