Trace Lines for Classification Decisions

Referral, placement, and retention decisions were analyzed using item response theory (IRT) to investigate whether classification decisions could be placed on the latent continuum of ability normally associated with test items. A second question pertained to the existence of classification differential item functioning (DIF) for the various decisions. When the decisions were calibrated, the resulting "item" parameters were similar to those that might be expected from conventional test items. For classification DIF analyses, referral decisions for ethnicity were found to be functioning differently for Whites versus non-Whites. Analyzing decisions represents a new unit of analysis for IRT and represents a powerful methodology that could be applied to a variety of new problem types.