There are screening tests that can be given to preschoolers or kindergarteners to determine if a child is “at risk” for reading difficulty. Since preventive interventions are highly effective, it’s a good idea to check into this, particularly if there is a family history of reading and spelling diffculties. Tests for children this age will measure ability to blend sounds into words, ability to manipulate sounds, ability to remember random information (phonological memory), and ability to rapidly name known items.
For children who have reached school age, a thorough evaluation will include tests of oral language skills (listening and speaking), phonological processing skills, alphabet/phonics knowledge, single word reading, spelling, and paragraph reading speed, accuracy, and comprehension. Since many research studies have shown that intelligence does not predict reading/spelling development, IQ testing is not necessary for a dyslexia diagnosis.