The Independent School Entrance Exam (ISEE) Upper Level is a popular admissions test taken by American students applying to private US high schools for grades 9-12. It is developed and marketed by the non-profit Educational Records Bureau (ERB).

Students receive about 3-hours to complete the 161-question ISEE, which is comprised of 4, separately scored sub-tests and a non-scored essay:

  1. Verbal Reasoning
  2. Quantitative Reasoning
  3. Reading Comprehension
  4. Mathematics Achievement
  5. Essay

Click here for a more in-depth look at strategies for the ISEE from our free ISEE Ultimate Prep Guide.

What is a Good Score on the ISEE

For every section of the ISEE except the essay, students receive a score between 1 and 9 called a “stanine.” 1 is the worst score, and 9 is the best score.

  • Stanine scores of 1, 2, and 3 represent the bottom 25% of test-takers.
  • Stanine scores of 4, 5, and 6 are average and represent the middle 50% of test-takers.
  • Stanine scores of 7, 8, and 9 are the highest and represent the top 25% of test-takers.

The ISEE like most standardized tests including the ACT and SAT is a peer-normed test, meaning that students are scored relative to each other. Specifically, students taking the ISEE are scored relative to all students who took the ISEE over the past 3-years, which is called the “norm group.” Note that there’s no need to sabotage a friend’s scores, because the norm-group does not include the current year of test-takers.

We Analyzed ERB’s Official Practice Tests to Identify What’s Tested and How

The ISEE test’s maker ERB makes two practice tests available to students. The first is a near full-length test available free of charge as a PDF as part of the official, “What to Expect on the ISEE” (WTE) guidebook. This test isn’t quite full-length, because it excludes the 21 so-called “experimental questions.”

The second practice test is full-length but only available as part of a $380 package sold exclusively by a for-profit test prep company. We think it’s unethical and usurious to charge $380 for the only publicly-accessible full-length ISEE practice test. Nevertheless, we allowed ourselves to get gouged so that you wouldn’t have to.

We analyzed both the free test in the WTE document (“free test”) and the $380 test (“$380 test”) that is only available behind a paywall from Test Innovators. Our summary analysis from each test follows below.

How to Access Official ISEE Practice Questions for Free

In the latest revision of the ERB’s What to Expect on the ISEE PDF from summer of 2020, the ERB removed the Sample Test Questions and Essay section and replaced it with a Section Strategies and Essay section.

The only difference between the 2020 and 2018 WTE is that ERB removed all of the 29 sample test questions. It didn’t remove the questions because they were out of date. It removed the questions so that it could better charge $380 for them—in fact 80% of the formerly free practice questions now appear in the $380 test.

Our analysis of the $380 test found that these formerly free practice questions are near perfect examples of what to expect on the ISEE in terms of difficulty. Our advice is to skip the $380 test and simply download last year’s “What to Expect on the ISEE” for free. Our analysis below uses excerpts from the free WTE document.

What is Tested on the ISEE Verbal Reasoning Section

The first section of the ISEE is Verbal Reasoning, which lasts 20 minutes and includes 40 multiple-choice questions. There are two question types—synonyms and sentence completions. Both question types test a student’s ability to recognize and use vocabulary.

What We Learned from the ERB’s Official Materials for Verbal Reasoning

Students are tested on their ability to define and/or use 138 vocabulary words, which show up as synonyms, fill-in-the-blank sentence completions, and their answer choices:

  1. These words can be very difficult, and on average appear in 0.0025% of all the words that comprise Google’s digitized book library.
  2. The vocabulary words are fairly evenly distributed between nouns, verbs, and adjectives.
  3. The construction of sentence completion questions are mostly comparing, contrasting, or cause-and-effect.

ISEE Vocabulary Words are Difficult

screenshot from Google ngrams for vocabulary word

To objectively analyze the difficulty of the vocabulary words, we examined every word using the Google Books Ngram Viewer, which details how frequently a word is used in literature published between 1950 and 2019 as an average percent. This analysis showed that the ISEE words appear in about 0.0025% of Google’s database, which includes words like “eliminate” and “artificial.”

For example, the word “chagrin” comprises just .0001% of the published words in Google’s database in 2019. By contrast, the word “the” represents 4.2% of the words in that same database.

The following histogram shows the number of words in each category (note that a lower percentage means a less commonly used and therefore more difficult word).

bar chart showing distribution of ISEE vocabulary words by difficulty level

Our analysis shows that the $380 test uses much less-common / more difficulty vocabulary words than the free test.

To put this data in context, a word like “felicity” (from the $380 test) appears approximately 0.00008% of the time while a word such as “initial” (from the free test) appears approximately 0.008% of the time. This means that the word “initial” is 100 times more common! This finding also aligns with the intuition that many people have about these words.

On average, the $380 test uses words that show up 0.001% of the time, while the free test uses words that show up 0.004% of the time. This may not seem like a large difference, but that actually means that the vocabulary that is tested on the free test is 4 times more common than that on the $380 test.

Distribution of Nouns, Verbs, and Adjectives on the ISEE Verbal Reasoning Section

Part of Speech Free ISEE Test $380 ISEE Test Average
Nouns 30.23% 30% 30.11%
Verbs 37.21% 34% 35.6%
Adjectives 32.56% 36% 34.28%

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Sentence Structure of Fill-in-the-Blank Verbal Reasoning Questions

The ISEE Upper Level test contains both single blank and double blank sentence completion questions. The sentences can be broken down by type, which can be helpful in teaching students what key words to look for to better understand what the missing word might be (key words are bolded in the samples below):

  • Compare and Contrast – “Unlike other great apes, which are social, orangutans are —– creatures except for playful juveniles and mothers with babies.”
  • Similarity – “Many people raise their voices in an argument, as though higher volume —– a greater ability to persuade.
  • Cause and Effect – “The article on gene splicing was so —- that only a handful of the students were able to understand it.”
  • Definition or Explanation – Poet-novelist Rita Dove, former United States Poet Laureate, was the —- of the 1966 Heinz Award in the category of arts and humanities.”
Sentence Type Free ISEE Test $380 ISEE Test Average
Compare and Contrast 33.33% 28.57% 30.95%
Similarity 27.78% 42.86% 35.32%
Cause and Effect 16.67% 28.57% 22.62%
Definition or Explanation 22.22% 0% 11.11%

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Click here for an even more in-depth look at the ISEE Upper Level Verbal Reasoning section from our free Ultimate ISEE Prep guide.

What is Tested on the ISEE Quantitative Reasoning Section

The second section of the ISEE is Quantitative Reasoning, which lasts 35 minutes and includes 37 multiple-choice questions. Many students consider Quantitative Reasoning to be the most challenging section of the ISEE.

What We Learned from the ERB’s Official Materials for Quantitative Reasoning

  1. The average question difficulty is a 3.4 out of 5 (see description below).
  2. Including answer choices, there are 0.55 graphics per question.
  3. Perimeter, area, and angles represented the most frequently tested concepts.

We used two metrics to create a 1-5 difficulty scale for the quantitative reasoning math questions.

  1. Length of time required to read and solve the problem.
  2. Number of distinct concepts required to solve the problem.

For example, we would rate the single concept question below as a 2 out of 5 for difficulty:

  1. If * = 4n + 3, what is the value of 8 *?
    1. 35
    2. 40
    3. 44
    4. 46

This problem is simply asking students to substitute 8 for each instance of n. This is not a particularly challenging task but does require students to understand the basics of function notation, so it is slightly below average difficulty and would be rated a 2.

We would rate this multi-step, multi-concept question a 4 out of 5 for difficulty:

  1. If the sum of all integers from 1 to 1,000, inclusive, is x, then which expression represents the sum of all integers from 1 to 998, inclusive?
    1. x – 1,999
    2. x – 999
    3. x + 999
    4. x + 1,999

This problem is clearly much harder than many others. It requires students to understand that x = 1 + 2 + 3 + … + 998 +999 +1,000 and then realize that subtracting 999 and 1,000 from both sides will give us that x – 1,999 = 1 + 2 + 3 + … + 998. This realization does not come easily to almost any student. However, it is not quite a 5 in difficulty as it only requires the student to represent one algebraic equation and perform simple arithmetic on it. This makes the problem above average, but not a 5 in difficulty.

With the two metrics mentioned above, the average difficulty of the questions from the free test and the $380 test was 3.44.

Graphics Make Questions More Manageable

The number of graphics on each test also plays a role in how students understand and interact with the math tests as a whole. Graphics, in our experience, generally aid students to better understand the problem and have a more concrete representation of the problem at hand.

Across both the free and $380 test, we found that there were an average of 20 graphics in the Quantitative Reasoning section or 0.55 graphics per question including the answer choices.

  Free ISEE Test $380 ISEE Test Average
Number of Graphics 21 19 20
Graphics per Question 0.66 0.51 0.55

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Tested Math Topics and Question Counts on the ISEE Quantitative Reasoning Section

Category Free ISEE Test $380 ISEE Test Average
Balancing Algebraic Equations 1 2 1.5
Data Analysis 4 1 2.5
Distance, Rate, & Time 1 0 0.5
Factors & Multiples 0 1 0.5
Fractions & Decimals 0 3 1.5
Function Notation 2 1 1.5
Linear Equations & Their Graphs 1 0 0.5
Mathematic Properties 2 0 1
Mean, Median, Mode, Range, & Weighted Average 2 4 3
Multiplying Polynomials 2 1 1.5
Operations on Algebraic Expressions 0 2 1
Order of Operations 3 1 2
Percentages 2 1 1.5
Polygons: Angles, Perimeter, and Area 5 7 6
Probability 3 3 3
Quadratic Equations and Their Graphs 1 0 1
Scientific Notation 0 2 1
Sequences 0 3 1.5
Set Notation 0 1 0.5
Solid Geometry: Surface Area and Volume 1 4 2.5
Systems of Linear Equations 1 0 0.5
Triangles: Types and Rules 1 0 0.5

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Click here for an even more in-depth look at the ISEE Quantitative Reasoning section from our free ISEE Ultimate Prep Guide.

What is Tested on the ISEE Reading Comprehension Section

The third section is Reading Comprehension, which lasts 35 minutes and includes 36 multiple-choice questions, which are evenly distributed among 6 reading passages.

What We Learned from the ERB’s Official Materials for Reading Comprehension

  1. The average passage length is 379 words across 53 lines.
  2. The average Flesch-Kincaid grade level is 4.93 (fifth grade).
  3. The types of passages were generally narrative (1), social sciences (2), Humanities (2), and Science (1).
Data Category Free ISEE Test $380 ISEE Test Weighted Average
Total Number of Lines 212 378 303
Total Number of Words 1523 2643 2235
Words per Passage 304.6 440.5 37
Flesch Kincaid Score 4.48 5.38 4.93

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The Flesch-Kincaid grade level score is a measure of the required grade level of education for a person to understand a passage based on the sentence length and number of syllables in the words; longer sentences and more syllabic words add up to make a more difficult passage. This analysis showed that the ISEE Upper Level reading passages are about a 5th grade difficulty level.

Reading Comprehension Subject Matter

The subject matter of the reading passages can also affect difficulty level. For example narrative fiction passages tend to be more familiar to students and easier for them to digest. Conversely dry science passages can often be more difficult for students to remain engaged and understand. We split the passage types into 4 main categories:

  1. Narrative
  2. Social Science
  3. Humanities
  4. Science
Passage Type Free ISEE Test $380 ISEE Test Average
Narrative 2 0 1
Social Science 2 2 2
Humanities 1 2 1.5
Science 0 2 1

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ISEE Reading Comprehension Question Types

Each of the 6 Reading Comprehension passages is followed by 6 questions. There are six types of questions.

  1. Main Idea – “The primary purpose of the passage is to”
  2. Supporting Ideas – “The author caused the larvae to decorate their cocoons with stripes by”
  3. Inference – “What probably led the author to experiment with caddis larvae”
  4. Vocabulary In Context – “In line 4, “minute” most nearly means”
  5. Organization and Logic – “Which best describes the organization of lines 8-17”
  6. Tone, Style, and Figurative Language – “The author’s tone when discussing the news media is best described as”

Our analysis shows that not all types of questions are present for every passage. Supporting Ideas questions occur the most often—more than one per passage—and tone, style, and figurative language questions occur the least often—only making an appearance once on about half of the passages.

Question Category Free ISEE Test $380 ISEE Test Average per Test
Main Idea 16.67% 13.89% 5.4
Supporting Ideas 23.33% 27.78% 9.2
Inference 16.67% 19.44% 6.5
Vocabulary 13.33% 19.44% 5.76
Organization and Logic 20% 13.89% 6.12
Tone, Style, and Figurative Language 10% 5.56% 3

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Click here for an even more in-depth look at the ISEE Reading Comprehension section from our free ISEE Ultimate Prep Guide.

What is Tested on the ISEE Mathematics Achievement Section

The fourth section is Mathematics Achievement, which lasts 40 minutes and includes 47 multiple-choice questions. Students generally find the Mathematics Achievement section easier than Quantitative Reasoning. However, our analysis shows that while the tested concepts in Mathematics Achievement may be generally easier than Quantitative Reasoning, more steps are often required to get the correct answer.

What We Learned from the ERB’s Official Materials for Mathematics Achievement

  1. The average question difficulty is a 3.5 out of 5 (see description of methodology above under Mathematics Achievement).
  2. Including answer choices, there are 0.38 graphics per question or 30% fewer than in Quantitative Reasoning.
  3. Data analysis represented the most frequently tested concept.

Like the Quantitative Reasoning section, the we analyzed the Mathematics Achievement section looking at:

  1. Length of time required to read and solve the problem.
  2. Number of distinct concepts required to solve the problem.

At just 0.38 graphics per question, there are fewer graphics in Mathematics Achievement versus Quantitative Reasoning.

  Free ISEE Test $380 ISEE Test Average
Number of Graphics 16 18 17
Graphics per Question 0.38 0.38 0.38

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Tested Math Topics and Question Counts on the ISEE Mathematics Achievement Section

As compared to the Quantitative Reasoning section, the Mathematics Achievement section tests a wider range of topics across the board.

Category Free ISEE Test $380 ISEE Test Average
Absolute Value 2 0 1
Arithmetic Word Problems 1 1 1
Balancing Algebraic Equations 2 0 1
Combinations 1 1 1
Data Analysis 6 4 5
Distance, Rate, & Time 0 3 1.5
Factors & Multiples 1 1 1
Fractions & Decimals 1 1 1
Function Notation 0 1 0.5
Inequalities 1 1 1
Linear Equations & Their Graphs 1 5 3
Mathematic Properties 0 1 0.5
Matrices 1 2 1.5
Mean, Median, Mode, Range, & Weighted Average 1 1 1
Midpoint & Distance Formulas 1 0 0.5
Multiplying Polynomials 1 0 0.5
Number Types 2 0 1
Operations on Algebraic Expressions 2 1 1.5
Order of Operations 2 1 1.5
Percent of Change 0 1 0.5
Percentages 0 1 0.5
Permutations 0 1 0.5
Polygons: Angles, Perimeter, and Area 4 6 5
Powers & Roots 2 2 2
Probability 3 4 3.5
Ratios & Proportions 1 0 0.5
Scientific Notation 1 1 1
Sequences 0 1 0.5
Solid Geometry: Surface Area and Volume 2 2 2
Triangles: Types and Rules 0 1 0.5
Trigonometry 1 0 0.5
Types of Angles 0 1 0.5
Units of Measurement 2 2 2

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Click here for an even more in-depth look at the ISEE Mathematics Achievement section from our free ISEE Ultimate Prep Guide.

What is Tested on the ISEE Essay

The essay is the fifth and final section but is not scored. Students are allowed 30 minutes to write up to two pages on a specific topic.

Their response is sent directly to schools. Schools mostly use the essay to get an idea of a literally-unadulterated look at a student’s writing ability and thought process.

Click here for a more thorough look at the ISEE Essay from our ISEE Ultimate Prep Guide.

Should You Buy the $380 Practice Test at Test Innovators

Our opinion is biased, but no, we don’t think you should spend $380 at Test Innovators just to acquire a single, recycled practice test from ERB. While the $380 test is significantly more difficult than the free test for Verbal Reasoning and Reading Comprehension, you can understand that difficulty just by downloading last year’s free “What to Expect on the ISEE” that includes excerpts from the $380 test or by taking Piqosity’s practice tests!

Piqosity for the ISEE Upper Level contains 10 full-length practice tests for just $99.
Register today for a 2-week free trial; no credit card is required!