Researchers strategically assess youth mental health by soliciting reports from multiple informants. Typically, these informants (e.g., parents, teachers, youth themselves) vary in the social contexts where they observe youth. Decades of research reveal that the most common data conditions produced with this approach consist of discrepancies…

Work on item response theory was extended to two areas not extensively researched previously, including models for: (1) test items that require more than one ability for a correct response (MIRT); and (2) interaction between modules of instruction that have a hierarchical relationship (HST). In order to develop the MIRT and HST models, the author…