the impediment this student faced, her lack of visual acuity, was unrelated to the content and skills the test was designed to measure. In the ugly jargon of the trade, she faced “construct-irrelevant” barriers to performing well on the test. Therefore, the effects of the disability on her performance on the standard test were clearly bias: if given the exam in standard form, her score would imply a lower level of mastery than she had actually attained. If we could find an accommodation that would do nothing but offset this impediment, validity would be increased.
