ABSTRACT
This chapter presents how the use of differential person functioning (DPF) in conjunction with differential item functioning (DIF) can minimize the tangible and intangible costs of test fraud, in addition to maximizing the measurement integrity and validity associated with exams with this known security issue. The number of candidates and items detected through the combined DPF and DIF approach varies depending on the flagging criteria selected, with the decision on flagging thresholds customizable to each respective exam's context and purpose. Additionally, these methods offer little assistance to identify specific compromised content despite giving some indication of the overall extent of exposure. The combined use of DPF and DIF enhances a test program's ability to maintain credible exams within a context of prevalent test fraud by detecting suspect candidates by their aberrant exam scores by item status. It includes identifying compromised and secure items based on bias towards or against candidates flagged for item preknowledge.
