Multistage Testing in Heterogeneous Populations: Some Design and Implementation Considerations.

A central challenge in international large-scale assessments is adequately measuring dozens of highly heterogeneous populations, many of which are low performers. To that end, multistage adaptive testing offers one possibility for better assessing across the achievement continuum. This study examines the way that several multistage test design and implementation choices can impact measurement performance in this setting.

Checking Equity: Why Differential Item Functioning Analysis Should Be a Routine Part of Developing Conceptual Assessments.

We provide a tutorial on differential item functioning (DIF) analysis, an analytic method useful for identifying potentially biased items in assessments. After explaining a number of methodological approaches, we test for gender bias in two scenarios that demonstrate why DIF analysis is crucial for developing assessments, particularly because simply comparing two groups' total scores can lead to incorrect conclusions about test fairness. First, a significant difference between groups on total scores can exist even when items are not biased, as we illustrate with data collected during the validation of the Homeostasis Concept Inventory.