ISEE Upper Level common mistakes
ISEE Upper Level · Understand the traps and how to avoid them.
On synonym questions, picking the answer that merely sounds sophisticated or is loosely associated with the prompt word rather than a true synonym (e.g., choosing 'lucid' for 'pellucid' when 'transparent' is closer, or choosing a word that only shares a topic).
ISEE Upper Level synonyms use high-frequency academic vocabulary and the distractors are deliberately related in topic or connotation but wrong in precise meaning; candidates under time pressure substitute a 'feels right' association for a definition check.
What to do instead
Before looking at options, write a one-word definition of the prompt word. Eliminate any option that does not match that definition, then check the remaining option by plugging it into a sentence: 'X means ' and reverse it (' means X'). Build a running list of synonym pairs you missed and drill them by definition, not by recognition.
On sentence completion, choosing a word that fits the blank grammatically and tonally but ignores the logic signal (contrast, cause, result) in the sentence, so a positive word is placed where the sentence requires a negative one.
Candidates read for overall gist and let the sentence's topic pull them toward a plausible-sounding word; they skip identifying the transition word ('although', 'because', 'despite') that determines the blank's direction.
What to do instead
Cover the answer choices, read the sentence, and predict the blank's meaning and charge (+/-) before seeing options. Circle the transition word and mark whether the two clauses agree or oppose. Only then match an option to your prediction; reject any option with the wrong charge even if it sounds natural.
Misreading the question stem on quantitative comparison items and solving for the value of x instead of comparing Quantity A and Quantity B, or assuming the quantities are equal because a quick substitution works.
The QC format is unfamiliar and the stem is short, so candidates default to 'solve the equation' habits from school algebra; a single convenient value (like a positive integer) makes many inequalities appear equal.
What to do instead
For every QC item, test at least three values deliberately: a positive number, a negative number, and a fraction between 0 and 1 (plus zero when allowed). If any test produces a different relationship, the answer is 'cannot be determined'. Never assume equality from one successful substitution.
Spending disproportionate time on one hard word problem or geometry item, leaving later questions unanswered, and losing points that were easily winnable.
ISEE Upper Level is scored on correct answers with no penalty for wrong answers, so there is no strategic reason to leave blanks, yet candidates treat each question as mandatory and get anchored on a single item.
What to do instead
Adopt a two-pass strategy: answer every question you can within roughly 60-75 seconds, mark hard ones, and return only after the section is complete. Since there is no wrong-answer penalty, fill in a guess for every remaining item before time expires. Practice with a timer to internalize the pacing.
Answering reading comprehension questions from prior knowledge or personal opinion instead of from the passage, and choosing an option that is true in the real world but unsupported by the text.
The passages are often about science or history where candidates have background beliefs; the distractors are written to sound reasonable and true, so outside knowledge feels like evidence.
What to do instead
For every answer, return to the passage and locate the sentence or phrase that supports it; if you cannot point to a line, the option is wrong. Treat 'supported by the passage' as the sole criterion. For inference questions, require that the answer be a small, necessary step from stated text, not a plausible extension.
Confusing main idea with a supporting detail, or selecting a 'main idea' option that is too broad (covers the whole topic area) or too narrow (covers only one paragraph).
Candidates latch onto the first or most memorable paragraph and mistake its content for the author's overall point; they also equate length or confidence of an option with correctness.
What to do instead
After reading, state the author's purpose in one sentence in your own words before looking at options. Test each option against the whole passage: does it cover the beginning, middle, and end? Eliminate options that describe only one paragraph (too narrow) or that could describe any article on the topic (too broad).
On vocabulary-in-context questions, choosing the most common dictionary meaning of a word rather than the meaning it carries in the passage's specific sentence.
Candidates know the dominant definition and answer from memory without re-reading the sentence; ISEE deliberately selects words used in a secondary or figurative sense.
What to do instead
Return to the sentence and substitute each answer choice into the original sentence, reading the whole sentence aloud mentally. Keep only the choice that preserves the sentence's logic. Ignore what the word 'usually' means; the passage's usage governs.
Making arithmetic and algebra errors on multi-step problems by working mentally, dropping negative signs, or mishandling fractions and order of operations under time pressure.
The Mathematics Achievement section rewards speed, and candidates skip writing intermediate steps to save time, which converts small sign or fraction errors into wrong answers on otherwise understood problems.
What to do instead
Write every step, including sign changes and fraction conversions, on scratch paper. Use a consistent layout (one column per step) and re-read the final line to confirm it answers the question asked. Practice fraction and negative-number operations until they are automatic, and estimate the answer first so a gross error is visible.
Misapplying formulas for area, volume, percent change, or slope by using the wrong dimension (radius vs. diameter, base vs. height) or by confusing percent increase with percent of.
Formulas are memorized as strings without the geometric or proportional meaning attached, so candidates plug numbers into the wrong slot; percent problems are especially prone to base-value confusion.
What to do instead
Before computing, label each given value with what it represents (r, d, h, original, new) and write the formula with units. For percent problems, identify the base explicitly and use (new - old)/old for change. Draw a quick sketch for geometry to confirm which lengths are perpendicular or which is the radius.
Guessing on quantitative reasoning items without eliminating any options, and failing to use answer-choice structure (e.g., testing the middle value or working backward from options) as a solving tool.
Candidates treat multiple choice as a last resort and either solve fully or guess blindly, missing the efficiency gain from backward substitution and estimation on items designed to be solved that way.
What to do instead
When an equation or inequality looks messy, plug answer choices in from the middle (test B or C first) and use the result to eliminate half the options. Use estimation and number sense to remove impossible magnitudes before guessing. Practice recognizing when backward solving is faster than forward algebra.