Dyslexia Testing

Assessing reading is simultaneously straightforward and complicated.  Many schools conduct testing at the most basic level to simply identify students who are performing below grade and/or age level in reading. This can be accomplished with administration of formal achievement tests (most commonly the WIAT-4, WJ IV ACH, GORT-5, and NDRT) that evaluate reading comprehension, rate, and fluency.  This process can be completed in under an hour but does not include any inference about etiology.

If the evaluator is trying to determine whether the student has a learning difference that transcends educational inadequacies and will require ongoing accommodations in reading (i.e., dyslexia), testing is more extensive. Formal achievement testing is still required, but fluid intelligence testing is also needed to determine whether a proper dyslexia diagnosis is warranted. The fluid intelligence testing is ideally conducted using the Wechsler testing batteries, which are what most dyslexia research is based upon and considered the gold standard. A thorough, targeted dyslexia test generally takes 2 to 3 hours.

Frequently, measures of phonetic processing and visual processing speed are also administered to help identify the student’s strengths and weaknesses, as the information obtained can help guide specific intervention strategies. Then achievement scores are compared not only to averages for the student’s age and grade, but also to their own predicted reading level given their overall intelligence in order to identify any significant discrepancy between the two. If the student is determined to be underachieving in reading given their intellectual potential, both evidence-based reading instruction and school accommodations are recommended.