The CASC Framework: An Assessment Model for Students With Intellectual and Developmental Disabilities

School psychologists pay a critical role in providing assessment and intervention services within the realm of special education. Within this role, they are highly likely to interact with students with intellectual and developmental disabilities (IDD). Students with IDD are characterized by significantly lower than average cognitive and daily living skills that may be comorbid with difficulties with communication, social skills, or other domains. With these differences in mind, dominant assessment practices have been criticized as lacking social and empirical validity when applied to this population. Although students with IDD frequently undergo evaluations, they continue to face significantly poorer post-school outcomes and family school partnerships than their peers within and outside of special education. In light of this, following a content analysis and review of assessment issues that relate to students with IDD, the Collaborative-Adaptive Student Centered (CASC) framework of assessment is proposed. This approach unites the core values of alternate models of assessment in order to promote school psychology practices that improve self-efficacy for students with IDD, integrate family voice in assessment, holistically collect student data, and apply process testing methods. Finally, while the CASC model described and within Manuscript One has the potential to improve affairs for students with IDD, it also represents persistent calls for paradigm shifts that have failed to come into fruition for school psychologists. Consequently, Manuscript Two describes findings from the Survey of Comprehensive Assessment Practices (S-CAP). The S-CAP was distributed to practicing school psychologists to better understand their assessment practices with students with IDD. Specifically, the S-CAP investigated (a) the assessment practices utilized by school psychologists in their work with students with IDD, (b) variables related to assessment practices described within the CASC framework, and (c) school psychologist perception of traits that would facilitate improved assessment with students with IDD and barriers to the enactment of these traits. School psychologists’ attitudes regarding assessment as a therapeutic tool and family-school collaboration was explored in order to identify whether these attitudes predict practices that are aligned with the CASC model. In summary, Manuscripts One and Two aim to initiate real change in the assessment practices that school psychologist apply to their work with students with IDD by considering unique practice-related variables through an integrated model and a survey of service delivery