How do I make sure that an alternate form of an exam is equivalent to the standard form?
In the process of teaching a course, instructors may find that the format of some tests is not fully accessible to students with particular types of disabilities. For example, a student with a fine motor impairment may not be able to fill in the bubbles on a Scantron sheet. A student with Dyslexia may have difficulty demonstrating mastery by writing an essay but may have more success with a fill-in or multiple-choice test. If an alternate form of a test is called for, instructors should ensure that the alternate form is equivalent to the test given to other students.
Test validity is the degree to which an assessment tool measures what it is designed to measure. Tests should have content validity, meaning that they represent the material actually taught in a balanced way. One way for an instructor to check for content validity is to show the tests to other instructors of the same class or subject and have them add or delete questions to create a balanced assessment instrument. Alternate forms of tests should also have concurrent validity. Concurrent validity is the degree to which the scores of two tests are in agreement. Instructors can test for concurrent validity by having a few competent students take both forms of the test. If the alternate form is valid, students will score roughly the same on both tests.
It is important to make testing accommodations for students with disabilities in a way that a valid test results. This process is one way to assure that students with disabilities get the same high quality education as their nondisabled peers.