The ERB Comprehensive Testing Program (CTP 5) is the most widely used achievement assessment at top independent and private schools. Administered by the Educational Records Bureau (ERB), it tests verbal reasoning, quantitative reasoning, reading comprehension, writing mechanics, and mathematics — all scored against an independent school norm group, not a public school or national average.
Four core sections, each weighted equally. Scored against independent school norms — already a high-performing peer group — making every stanine point meaningful.
Section 1
Reading Comprehension
25%
of total score
Literary Passages~12%
Informational Passages~13%
Fiction, poetry, drama + history, science. Tests literal comprehension, inference, author's purpose, vocabulary in context.
Section 2
Verbal Reasoning
25%
of total score
Verbal Analogies~8%
Sentence Completion~8%
Verbal Classification~9%
Section 3
Quantitative Reasoning
25%
of total score
Mathematical Reasoning~13%
Number Sense & Patterns~12%
Reasoning and problem-solving, not pure computation. Similar to CogAT Quantitative Battery.
Section 4
Mathematics
25%
of total score
Arithmetic & Number (Lower)varies
Algebra & Geometry (Upper)varies
Content knowledge scored vs. independent school norms. Writing Mechanics (capitalization, punctuation, grammar) administered separately.
Full Content Outline
ERB CTP 5 Topic Breakdown
Every question type your child will encounter, with strategies specific to the independent school norm group. Click each section to expand.
Reading Comprehension25%
Passage Types
The CTP 5 uses more challenging texts than public school assessments — passages are drawn from classic and contemporary literature, primary historical sources, and academic science writing.
›Literary: fiction (short stories, novel excerpts), poetry, drama scripts
›Informational: history, science, biography, social studies
›Texts are 1–2 grade levels above typical public school reading lists
Question Types & Strategies
›Literal comprehension: directly stated facts
›Inference: what the text implies but doesn't state
›Author's purpose and tone questions
›Vocabulary in context (not memorized definitions)
›Strategy: always return to the passage; never answer from memory
Verbal Reasoning25%
Analogy Types (A:B::C:?)
Vocabulary is the #1 differentiator on the CTP verbal section. Analogy types include:
The CTP uses significantly more advanced vocabulary than public school analogies. Independent school students score the highest differential here. Vocabulary depth is the biggest prep lever.
Sentence Completion & Classification
›Single-blank sentences with challenging vocabulary choices
›Double-blank sentences (upper levels) — both blanks must fit
›Verbal classification: identify the category connecting three words
Quantitative Reasoning25%
Reasoning vs. Computation
The CTP Quantitative Reasoning section does NOT test memorized math facts. It tests mathematical thinking — the ability to reason about quantities and relationships.
The CTP reports stanines and percentiles — but the norm group is independent school students, which changes everything.
Stanine vs. Independent School Norm
A stanine 5 on the CTP means average for private school students — already very high vs. national norms. Stanine 5–6 is solid; 7–9 is excellent.
1–4
Below avg
5–6
Solid
7–9
Excellent
Percentile (Independent School)
50th percentile on CTP ≈ 70th–75th percentile nationally. Always clarify which norm group is referenced when interpreting your child's score.
50th pct CTP
≈ 70th–75th pct nationally
Scaled Score
Internal score used for longitudinal tracking. Not typically shared directly with parents. Stanine and percentile are the reported parent-facing metrics.
Study Materials
Recommended ERB CTP 5 Books
Handpicked study guides. Affiliate links — we earn a small commission at no extra cost to you.
The Gifted Child's Guide to Private School Testing
Comprehensive prep for independent school assessments including ERB CTP with full practice sections.
The ERB Comprehensive Testing Program (CTP 5) is an achievement test used by independent and private schools to assess student learning across verbal reasoning, reading comprehension, quantitative reasoning, mathematics, and writing mechanics. It is produced by the Educational Records Bureau (ERB).
Who takes the CTP?
The CTP is administered at private and independent schools across grades 1–11. It is also used by some schools for admissions benchmarking. Students at ERB-member schools take it as part of the school's standard assessment program.
How is the CTP scored?
CTP scores are reported as stanines (1–9 scale) and percentiles, both normed against a national independent school comparison group. A stanine 5 means average for private school students — already well above the national public school average.
What is a good CTP score?
Stanines 7–9 are considered excellent and place a student in the top 23% of independent school peers. A stanine 5–6 is solid. Because the comparison group is already high-performing, any stanine above 5 is strong relative to the national average.
How is CTP different from ISEE/SSAT?
The CTP is an achievement test administered within a school — it measures what students have learned across academic subjects. The ISEE and SSAT are admissions tests that students take externally to apply to private schools. The CTP is ongoing; ISEE/SSAT are one-time application tests.