Often it is infeasible or unethical to use random assignment in educational settings to study important constructs and questions. Hence, educational research often uses observational data, such as large-scale secondary data sets and state and school district data, and quasi-experimental designs. One method of reducing selection bias in estimations…

When administering tests across grades, vertical scaling is often employed to place scores from different tests on a common overall scale so that test-takers' progress can be tracked. In order to be able to link the results across grades, however, common items are needed that are included in both test forms. In the literature there seems to be no…