Maintaining a precise, invariant unit in state, national and international educational assessment. School achievement testing is a high stakes activity for state and national governments, not just for school students. Significant educational policy decisions turn on comparisons of test results over time, and among states and nations. These decisions rest on assumptions about the validity and precision of national testing. In particular, current measurement systems assume that assessment scales h ....Maintaining a precise, invariant unit in state, national and international educational assessment. School achievement testing is a high stakes activity for state and national governments, not just for school students. Significant educational policy decisions turn on comparisons of test results over time, and among states and nations. These decisions rest on assumptions about the validity and precision of national testing. In particular, current measurement systems assume that assessment scales have common units. Empirically, it is clear that many factors can compromise this assumption, making it rarely justified. This study will serve the national interest by building the theory and technology necessary to solve this problem.Read moreRead less
Maintaining invariant scales in state, national and international level assessments. Large scale assessments involve comparisons between countries, states within a country, and within these over time. For many reasons, identical items cannot be administered to every student. Nevertheless, the items must operate invariantly across groups. The Rasch models, which have invariance as an intrinsic property, are powerful in checking for such invariance. This project brings the basic research of the ....Maintaining invariant scales in state, national and international level assessments. Large scale assessments involve comparisons between countries, states within a country, and within these over time. For many reasons, identical items cannot be administered to every student. Nevertheless, the items must operate invariantly across groups. The Rasch models, which have invariance as an intrinsic property, are powerful in checking for such invariance. This project brings the basic research of the Chief Investigators to the industry partners to study, apply and document ways in which violations of Rasch models and different data collection formats are reflected as changes of scale, and how these might be controlled both statistically and empirically.Read moreRead less