By The OpenKidsPrep Editorial Team
Your district uses either the NNAT or the CogAT for gifted screening — or in some cases, both. Understanding the core differences between these two tests matters for how you prepare your child, how you interpret scores, and what those scores tell you about your child's strengths. This article explains the key distinctions from the ground up.
The Head-to-Head: At a Glance
| Feature | NNAT | CogAT |
|---|---|---|
| Publisher | Pearson (Naglieri) | Riverside Insights (Lohman) |
| What it tests | Nonverbal reasoning only | Verbal + Quantitative + Nonverbal reasoning |
| Number of questions | 48 | ~176 (across 9 subtests) |
| Testing time | ~30 minutes | 2.5–3 hours (often split across days) |
| Score scale | NAI: mean 100, SD 15 | SAS: mean 100, SD 16 |
| Language content | Zero — fully nonverbal | Significant verbal component |
| Age or grade normed | Age-normed | Age-normed |
| Levels | A–G (7 levels) | 5/6–17/18 (by age, Forms 7–8) |
| Gifted cutoff (typical) | 95th+ percentile | 95th+ percentile (composite or battery) |
The Core Difference: Nonverbal Only vs Three Batteries
The single most important difference between the NNAT and CogAT is scope. The NNAT is 100% nonverbal — every question uses geometric shapes and visual patterns, and no reading or language is required at any point. The CogAT has three separate batteries:
- Verbal Battery — verbal analogies, sentence completion, verbal classification
- Quantitative Battery — number analogies, number series, equation building
- Nonverbal Battery — figure matrices, paper folding, figure classification
The CogAT's Nonverbal Battery and the NNAT cover overlapping ground — both measure visual pattern reasoning. But the CogAT Verbal and Quantitative batteries have no counterpart on the NNAT at all. A child taking the CogAT is being measured on three fundamentally different types of reasoning; a child taking the NNAT is being measured on one.
Why the NNAT Is Language-Fair
Because the NNAT contains no words anywhere — not in the questions, not in the instructions (which are often delivered orally by the examiner), and not in the answer options — it is considered a language-fair assessment. This makes it particularly valuable in two contexts:
English Language Learners (ELL)
A child who speaks Mandarin, Spanish, or any other first language at home is not disadvantaged on the NNAT the way they might be on the CogAT's Verbal Battery. Gifted programs that want to identify ability across all language backgrounds — without filtering out children because of English proficiency — frequently prefer the NNAT.
Children with Language-Based Learning Differences
A child with dyslexia, auditory processing differences, or other language-processing challenges may score very differently on a purely visual test vs a test with verbal components. The NNAT can reveal nonverbal reasoning ability that verbal tests mask.
NYC's G&T program uses the NNAT precisely because of this language equity consideration — the city's student population is among the most linguistically diverse in the country.
Format and Time Commitment
For families, the practical difference in test length is significant. The NNAT is a single 30-minute session with 48 questions. Most young children can sustain focus for 30 minutes without difficulty.
The CogAT, by contrast, spans 9 subtests totaling roughly 2.5–3 hours of testing time. In school settings, it is typically administered over two or three separate sessions spread across different days. This adds up to a meaningfully larger commitment — both in prep time and in the child's stamina on test days.
For students taking both tests in a single testing cycle (which some districts require), the CogAT preparation investment is significantly higher.
Score Comparison: Similar Scales, Different SDs
Both the NNAT and CogAT report standard scores with a mean of 100, but their standard deviations differ:
- NNAT — Naglieri Ability Index (NAI): mean 100, SD 15
- CogAT — Standard Age Score (SAS): mean 100, SD 16
This difference is small but worth knowing when comparing scores across the two tests. An NAI of 130 on the NNAT (2 SDs above mean) places a child at approximately the 98th percentile. A CogAT SAS of 130 places a child at approximately the 97th percentile — slightly different because of the wider SD. Neither score is directly comparable to the other in any meaningful clinical sense; they measure different things on different scales.
Which Is Harder?
This is the question most parents ask, and the honest answer is: it depends on your child's profile.
- CogAT is longer and more comprehensive. With three batteries and 9 subtests, it demands more stamina, broader preparation, and tests a wider range of abilities. A child who struggles with either verbal or quantitative reasoning will have a harder time on the CogAT than a child who is strong across all three areas.
- NNAT questions can feel harder per question because the test is purely abstract. On the CogAT, verbal questions give word-oriented children something to grip. On the NNAT, there are no words at all — every question requires pure visual-spatial reasoning, which some children find more demanding.
- For ELL students and spatial thinkers, the NNAT is often the easier test because it removes the language barrier entirely. These children may score significantly higher on the NNAT than on any battery of the CogAT.
Which Districts Use Which Test?
There is no universal standard. District test choice depends on state policy, district philosophy, and publisher contracts:
- NNAT-heavy districts: New York City, parts of Florida, Texas, and California districts with large ELL populations often favor the NNAT for its language fairness.
- CogAT-heavy districts: Iowa (where CogAT originated), Illinois, and many Midwest and suburban districts use the CogAT. It is also commonly used as a universal screener given across entire grades.
- Districts using both: Some districts use the CogAT as their universal screener and the NNAT as an additional tool for ELL students or as a secondary confirm screen. NYC uses NNAT + OLSAT (not CogAT).
Always confirm which test your specific district uses before beginning prep. Mixing up NNAT prep strategies with CogAT Verbal prep wastes valuable preparation time.
Prep Strategies: Overlap and Divergence
Shared prep strategies (useful for both tests):
- Matrix puzzles (3×3 grids with shapes following rules) — directly tested on both NNAT Serial Reasoning and CogAT Figure Matrices
- Pattern recognition activities — sequences, visual analogies, shape classification
- Timed practice to build stamina and test-taking comfort
- Test familiarity work — understanding the question format and knowing to always provide an answer
NNAT-only prep:
- Spatial visualization (folding, rotating shapes mentally) — appears on NNAT levels E and above, not on CogAT in the same format
- Pattern completion (filling the missing piece of a large shape) — the dominant question type at NNAT Levels A–C
CogAT-only prep:
- Verbal analogies ("dog is to puppy as cat is to ___")
- Number series and number analogies
- Sentence completion and verbal classification
- Equation building (upper grades)
If your child is taking the NNAT only, skip all CogAT Verbal and Quantitative prep entirely. There is no verbal or math content on the NNAT — preparation time spent on vocabulary lists and number series is completely wasted.
NYC Specifically: NNAT + OLSAT, Not CogAT
A common source of confusion for NYC families: NYC does not use the CogAT. The NYC G&T program uses the NNAT and OLSAT together. The OLSAT (Otis-Lennon School Ability Test) is a verbal reasoning test, but it is a different instrument from the CogAT Verbal Battery — different question formats, different norming, and a different composite formula. Do not substitute CogAT prep for OLSAT prep if you are in NYC.
For NNAT + OLSAT combined prep, see our NYC G&T guide and our OLSAT study guide.
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