Let’s unlock the ABCs of testing for dyslexia, and explain what is included in a comprehensive evaluation. Part of the reason this is SO important is that when you ask the local school to evaluate your child many of these tests are NOT included.
Good Grades Can Hide a Reading Problem
One of the biggest myths I run into occurs when an administrator tells you that if they’re passing classes, they don’t need to undergo a comprehensive evaluation. Wrong!!
Dyslexia has nothing to do with how bright your child is. In fact, many dyslexic students are incredibly bright. They compensate. They memorize. They avoid. They’re experts at guessing from context. But eventually, the workload spikes and they hit their brick wall. When that happens is different for each child. Remember, it goes back to dyslexia being on a continuum. The more severe the condition the earlier they will stumble. Vice versa, cases that are not severe (or where the child is twice exceptional) might be ignored or even pooh- poohed.
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Screening vs. Evaluation: What You’re Actually Asking For
Let’s separate two words that schools might treat as synonyms: screening and evaluation.
- A screening is a brief check. Think: “Is there something that we should look at closer?”
- A comprehensive evaluation is the deep dive. It looks at multiple skill areas to explain what as well as why.
If you’re requesting a comprehensive evaluation, you are asking for the deep dive. The kind of evaluation that can guide instruction, accommodations, and services. A quick screening will not identify the issues that your child is facing. You need a comprehensive evaluation.
So why do most schools not provide a comprehensive evaluation? Well, if you didn’t specifically request “a comprehensive evaluation” (those words exactly in writing), the school isn’t required to provide one. I’m not saying that schools are intentionally doing this, but sometimes you need to read between the lines. Testing can be complicated. Providing a comprehensive evaluation takes time and requires a level of expertise that most school psychologist don’t have. I like to think of Special Education programs at public schools as being like a triage system. They need to identify the students with severe conditions that prevent a student from learning. Visible cases make their job easier.
Dyslexia isn’t always visible because it’s brain-based and kids get really good at compensating, masking and avoiding. Let me share my daughter’s case. The school used the KTEA test (Kaufman Test of Educational Achievement. It’s a test many schools use to assess reading, writing, math and oral language. When my daughter took it in the 11th grade, she shared that it was a joke because it was so easy. The information being tested felt like something from elementary school. So, no surprise when the school said she was fine. It was only after some intensive research, that I discovered that the KTEA is an untimed test. Now let’s unpack that fact. The school administered an untimed test to a potentially dyslexic student to determine if there was an issue. Hmmm…what is one of the key factors for dyslexics? Timing!! They take longer to read, write and process information. If you are testing for dyslexia using an untimed test, you are not going to uncover an issue. Not exactly best practices.
What a Comprehensive Evaluation Measures
Let’s talk about the different areas that a comprehensive evaluation covers whether you are testing for dyslexia or another condition.
- Cognitive abilities (how your child thinks and processes information)
- Academic skills (reading, writing, spelling, math – the “school skills”)
- Phonological processing (the sound system of language)
- Reading accuracy, fluency, and comprehension (how reading looks in real time)
- Written language (spelling, sentences, organization)
- Auditory processing and memory (how your child takes in and holds sound-based information)
A comprehensive evaluation pulls data from multiple buckets. When I take on a new student, I always ask if there is a comprehensive evaluation so I can better understand the needs of the person I will be tutoring. Having this information helps paint a picture of the child. Let’s walk through the specific tests.
Cognitive Tests: WISC-V and WPPSI
You’ll usually see one of these in a comprehensive evaluation (psychoeducational or neuropsychological):
- WISC-V (Wechsler Intelligence Scale for Children – Fifth Edition) – typically ages 6 to 16
- WPPSI (Wechsler Preschool and Primary Scale of Intelligence) – for younger children
In plain English, these tests measure your child’s ability to think, reasons, solve problems, understand language, use visual-spatial skills, process and hold information in working memory.
Cognitive testing helps us rule out the myth that your child “just isn’t trying” or “isn’t capable.” It can also highlight profiles we commonly see with dyslexia:
- Working memory weaknesses (holding sounds/steps in mind)
- Processing speed weaknesses (doing basic reading/writing tasks quickly)
- A big gap between verbal reasoning and basic reading skills (bright thinker, struggling reader)
The subtests and index scores are important. The overall number can hide weaknesses in one which are only seen by looking at the subtests. You want to understand how working memory and processing speed may impact reading, spelling, note-taking, and timed tests.
Academic Achievement Tests: WIAT and Woodcock-Johnson
These tests look at what they do in school tasks
- WIAT (Wechsler Individual Achievement Test)
- WJ (Woodcock-Johnson Tests of Achievement)
They measure reading accuracy, reading comprehension, spelling, writing, and often math. These tests show where your child is performing compared to same-age peers. The norm-reference is vital because that is going to show you how your child compares to children across the entire United States and not simply in their school. Let me give you an analogy. Let’s say your 10-year-old child can lift 15 lbs. She trained for 3 months to do this and is extremely proud of her accomplishment. Now, how do you feel if I share that the average 8 year old can lift 20 lbs without any practice? It takes on a new light. That’s why norm referenced tests are an essential part of a comprehensive evaluation.
Why does this matter when testing for dyslexia ? Well, dyslexia is a specific learning disability in reading. You want to understand if the struggles are isolated to reading or part of a broader learning profile.
Academic areas need to look at reading and decoding. This includes single words (without context), nonsense words (phonics patterns); spelling and written expression; unusual patterns (strong listening comprehension but weaker reading comprehension).
Phonological Processing: CTOPP
CTOPP (Comprehensive Test of Phonological Processing) is one of the most important pieces of a dyslexia evaluation. The test measures sound-based skills that support decoding and spelling. These include:
- Phonological awareness (can they hear and manipulate sounds?)
- Phonological memory (can they hold sound information in mind?)
- Rapid naming (how quickly they can name letters/numbers/objects – a key predictor of reading fluency)
Dyslexia is often rooted in difficulty processing the sound structure of language. If the CTOPP shows weaknesses, it strongly supports the need for explicit, structured literacy instruction.
Kitchen-table translation: if your child can’t reliably hear, hold, and quickly access speech sounds, reading and spelling will feel like trying to build a house in the dark.
Real-Time Oral Reading: GORT
GORT (Gray Oral Reading Test) measures how reading sounds out loud in real time. The test measures:
- Accuracy (are words read correctly?)
- Rate (how fast?)
- Fluency (how smooth and automatic?)
- Comprehension (do they understand what they read?)
Some kids can decode slowly but accurately; others more quickly. The GORT helps differentiate these representations and validate what many parents say: “This is what reading actually looks like when my child opens a book.”
Word Reading Efficiency: TOWRE
TOWRE (Test of Word Reading Efficiency) is a short but powerful measure of automaticity and measures:
- Sight word efficiency (how quickly they read real words)
- Phonemic decoding efficiency (how quickly they read nonsense words)
Why it matters: dyslexia often shows up as slow, effortful word reading. Even if a child can decode, if it’s not automatic, comprehension and stamina take a hit. TOWRE helps document that effort.
Written Language: TOWL
TOWL (Test of Written Language) looks at writing beyond spelling.
What it measures: sentence structure, grammar, vocabulary use, and overall writing quality – depending on the version and subtests used. Many dyslexic students also struggle with written expression. They might have strong ideas but weaker spelling, sentence building, or organization. TOWL helps a parent understand the difference between not having anything to say from having a lot to say, but having problems getting onto paper.
Auditory Processing and Memory: TAPS
TAPS (Test of Auditory Processing Skills) often shows up in comprehensive evaluations, especially when listening, memory, or following multi-step directions is a concern. It measures: auditory memory, auditory cohesion (making meaning from what’s heard), and phonological aspects.
While TAPS is not the same as a full clinical test for Central Auditory Processing Disorder (CAPD), it can give useful information about how well your child holds and manipulates what they hear – which absolutely affects reading and spelling.
Older Students: Nelson-Denny Reading Test (NDRT)
For middle school, high school, and college-aged students, you may see the Nelson-Denny Reading Test when administering a comprehensive evaluation. This test measures: reading rate, vocabulary, and comprehension at higher levels – closer to the demands of secondary school and college.
This is essential for older students who don’t struggle because they can’t understand ideas. They struggle because reading takes too long, drains them, and leaves less brain space for learning content. NDRT can identify the mismatch between potential and output – especially for accommodations like extended time. Remember in the beginning of this post that my daughter was given the KTEA? The Nelson-Denny Reading Test would have been much more appropriate.
Summary
A comprehensive evaluation is about building a clear explanation and a plan. Break the recommendations into two buckets: interventions and accommodations. Most students benefit from both. Intervention changes the skill (we teach the brain to read more efficiently) while accommodations change access (we reduce the penalty while skills are developing). The comprehensive evaluation needs to connect recommendations to specific data points – not generic checklists.
If you’re requesting a comprehensive evaluation through the school, put it in writing. Use clear language like:
“I am requesting a comprehensive evaluation to determine whether my child has a specific learning disability in reading, (dyslexia), writing (dysgraphia) and math (dyscalculia). Please assess cognitive abilities, academic achievement, phonological processing, reading fluency, and written expression.” That phrasing matters. It signals you’re not asking for a quick screen.
Remember, seeking a comprehensive evaluation is not overreacting. The earlier you get clarity, the faster you can move from guessing to helping.
