Overview & Quick Facts
The ERB CTP (Comprehensive Testing Program) is a rigorous achievement test used by over 1,000 independent (private) schools for admissions and benchmarking. It assesses Reading, Vocabulary, Writing, and Mathematics at above-grade-level difficulty.
Quick Facts
Test Areas
Key Takeaway
CTP scores compare students to the ERB independent school norm group — other students in highly selective private schools across the country. Scoring at the 50th percentile on the CTP means performing at the average level for private school students — which is well above the general public school average.
How to Use This Guide
Use the chapter navigation on the left to explore each section in depth. Start with a specific question type to understand what's tested, then jump to the 4-Week Study Schedule when you're ready to prep.
Verbal: Reading & Vocabulary
The Verbal portion tests Reading Comprehension and Vocabulary. Both sections are above-grade-level in difficulty compared to most state tests.
Literary and informational passages with questions on main idea, inference, author's purpose, and literary analysis. Passages increase in complexity at higher grade levels.
Synonym and context-based vocabulary questions. CTP vocabulary is academically rigorous — reflects the reading level of strong independent school students.
Grammar, punctuation, and style editing questions. Some grade levels also include a Written Expression component with short constructed responses.
Mathematics
Two Math subtests: Concepts & Skills and Problem Solving. Both are above grade level in difficulty and require multi-step mathematical reasoning.
Number sense, operations, fractions, algebra concepts, geometry, and data interpretation. Tests mathematical understanding, not just procedural skill.
Multi-step word problems requiring strategy selection. The most challenging section — rewards students who can analyze novel problem situations and apply mathematical reasoning.
Score Interpretation
CTP scores are reported as percentile ranks within the ERB independent school norm group and as National Percentile Equivalents (NPE) for comparison to the general population.
Standard Score
Scores are reported against the ERB independent school norm group. The scale and range vary by grade level — ERB provides score interpretation guides to participating schools.
Percentile (IS Norms)
Compared to students in ERB-member independent schools. 50th percentile among IS norms = well above average nationally. Most schools look for 60th+ percentile for admissions screening.
60th+ pct IS
Target for selective schools
National Percentile Equivalent (NPE)
ERB also converts scores to a National Percentile Equivalent (NPE), comparing to the general population. This helps contextualize the independent school performance for families from public school backgrounds.
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Gifted Child & Private School Testing Guide
Parent guide to independent school admissions testing, CTP scores, and gifted programs.
Frequently Asked Questions
What is the ERB CTP?
The CTP (Comprehensive Testing Program) by ERB is used by over 1,000 independent (private) schools for admissions, placement, and academic benchmarking. It assesses Reading, Vocabulary, Writing, and Mathematics in grades 1–11.
What is the ERB norm group?
CTP scores are normed against students enrolled in independent schools — not the general population. The ERB independent school norm group represents a highly selected, academically strong population. Average CTP performance corresponds to far above-average in the general population.
How do private schools use CTP scores?
Schools use CTP scores to assess academic readiness, place students in appropriate course levels, and identify students who may need additional support or enrichment. Some schools require recent CTP scores (within 1–2 years) as part of the admissions process.
What is a good CTP score?
At the 50th percentile within independent school norms, a student is performing at the average for private school applicants — well above general population average. Selective schools look for the 60th–75th+ percentile within independent school norms for new admissions.
How can students prepare for the CTP?
The CTP tests curriculum-aligned content. Strong preparation includes: grade-level reading daily, vocabulary building, and math practice at or above grade level. There are no official "CTP prep books" — focus on academic excellence rather than test prep.