Psychometric Challenges in Assessing English Language Learners and Students With Disabilities

This chapter addresses the psychometric challenges in assessing English language learners (ELLs) and students with disabilities (SWDs). The first section addresses some general considerations in the assessment of ELLs and SWDs, including the prevalence of ELLs and SWDs in the student population, federal and state legislation that requires the inclusion of all students in large-scale assessments, validity considerations in the assessment of ELLs and SWDs, importance of test accommodations in their assessment, and an introduction to the psychometric challenges, which are intricately interwoven with validity and fairness considerations, in assessing ELLs and SWDs. The second section discusses the efficacy of test accommodations and modifications for SWDs and ELLs. The third section addresses the need for invariant measurement for ELLs and SWDs. In the assessment of a diverse student population it is important to examine the extent to which the psychometric properties of a test are invariant across groups of students. This necessitates obtaining evidence of reliability and score precision, internal structure evidence, external structure evidence, and evidence of equating invariance for ELLs and SWDs. The establishment of measurement invariance for ELLs and SWDs is required to make valid and fair score interpretations for these students and for group comparisons. Under the No Child Left Behind Act (NCLB) of 2002, growth measures have been implemented to help determine Annual Yearly Progress (U.S. Department of Education, 2005); however, the research on the efficacy of models for monitoring change for ELLs and SWDs has been scarce. Such research is crucial given that the federal Race to the Top initiative calls for multiple measures in educator evaluation systems, including measures that assess student progress (U.S. Department of Education, 2010). The last section addresses issues related to including SWDs and ELLs in measures of "growth" and of educator effectiveness.