ABSTRACT
Unnecessary linguistic complexity of assessments as a source of construct-irrelevant variance (CIV) may threaten the validity of interpretation of assessments for all students, particularly for English language learners (ELLs). Literature suggests that ELL students may have the knowledge in content areas, such as mathematics and science, but may not be at the level of English proficiency to understand test items and provide appropriate and detailed responses (Abedi & Lord, 2001). ELL students have a greater chance of responding incorrectly to test items with greater levels of linguistic complexity. Therefore, to the extent possible, this source of CIV should be reduced or eliminated by providing a linguistically accessible version of the test as a form of accommodation for ELLs or as an accessibility feature for all test takers, including ELLs (Abedi & Ewers, 2013; Thurlow, Lazarus & Christensen, 2013). As indicated in the Standards for Educational and Psychological Testing,
Test developers and/or test users are responsible for developing and providing test accommodations when appropriate and feasible, to remove construct-irrelevant barriers that otherwise would interfere with examinees’ ability to demonstrate their standing on the target constructs.
(American Educational Research Association [AERA], American Psychological Association & National Council on Measurement in Education, 2014, p. 67)