An essential concern in the application of any equating procedure is determining whether tests can be considered equated after the tests have been placed onto a common scale. This article clarifies one equating criterion, the first-order equity property of equating, and develops a new method for evaluating equating that is linked to this…

The purpose of this study is to determine the extent of scale drift on a test that employs cut scores. It was essential to examine scale drift for this testing program because new forms in this testing program are often put on scale through a series of intermediate equatings (known as equating chains). This process may cause equating error to…

Item parameter estimates derived through item response theory methods have been considered relatively robust to changes in item position and context, but the anomaly in reading scores from the 1986 National Assessment of Educational Progress (NAEP) illustrates problems with common population equating procedures when there are test form changes.…