Comparing screening approaches to investigate stability of common items in Rasch equating.
This paper used real and simulated data sets to compare three screening approaches often used in state-wide equating programs utilizing the Rasch model: Wright and Stone's t-statistic, robust z-statistic, and displace. Analyses of real data sets supported the superiority of robust z-statistic and displace measure relative to Wright and Stone's t-statistic. The simulation component did not support the contention that indiscriminate use of the +/-0.3 logits criterion inflates rates of Type I error for robust z-statistic and displace measure, although this contention was supported for the Wright and Stone's t-statistic. However, Type II error rates were largest for displace measure, followed by the robust z-statistic, then the t-statistic. The paper discusses the importance of a priori selection of a criterion for screening linking items and its effects on stability and accuracy of Rasch equating constant.
Arce-Ferrer
Alvaro J
AJ
Harcourt Assessment, Inc. Alvaro_arce-ferrer@Harcourt.com
D015982:Bias; D003627:Data Interpretation, Statistical; D004521:Educational Measurement / Q000379:methods* / Q000706:statistics & numerical data*; D006801:Humans; D015233:Models, Statistical; D014481:United States