ISEB Common Pre-Test common mistakes
ISEB Common Pre-Test · Understand the traps and how to avoid them.
Underlining or circling every proper noun and date in a comprehension passage as 'key', then answering inference questions with a literal phrase lifted from the text rather than a conclusion drawn from it.
Candidates are trained in primary school to highlight facts, and highlighting feels productive. When a question asks what a character 'probably felt' or what 'suggests' something, they reach for the most visually marked sentence instead of reasoning from clues such as actions, dialogue, and contrast words.
What to do instead
Practise sorting questions into 'right there' (literal) and 'read between the lines' (inference) before answering. For inference items, require yourself to name two pieces of evidence from different sentences and then state the conclusion in your own words; reject any answer option that merely repeats a phrase from the passage without adding meaning.
Treating 'not', 'except', 'least likely' and 'which is NOT' as invisible, so the candidate selects the one true statement when asked for the false one.
Under time pressure the eye skips short function words, and the brain defaults to confirming rather than negating. The three true options feel familiar from the passage, creating a false sense of having found the answer.
What to do instead
Adopt a physical routine: circle the negative word the moment it appears, then tick each option T or F against the passage before choosing. On any question containing a negation, re-read the stem once after selecting to confirm you answered the question actually asked.
Choosing an answer to a grammar or punctuation item because 'it sounds right' when read silently, without identifying the grammatical subject or the clause boundaries.
Silent reading supplies intonation the written sentence does not have, so a comma splice or a mismatched subject and verb can sound acceptable. Candidates also over-apply rules they half-remember, such as inserting a comma before every 'which' or after every fronted phrase.
What to do instead
For each item, name the subject and the main verb aloud or in writing before looking at options. For punctuation, mark each clause boundary with a slash and decide whether the two sides are full sentences, then choose the option that joins or separates them correctly.
Solving a multi-step word problem by grabbing the two numbers that appear together and applying the operation suggested by a keyword ('altogether' means add, 'left' means subtract), without checking units or what the question actually asks for.
Keyword spotting is a reliable shortcut in early primary maths and is hard to abandon. It fails when a problem contains a distractor number, mixes units (minutes and hours, pence and pounds), or asks for a remaining quantity after two operations.
What to do instead
Before calculating, write one line: what is given, in what units, and what single quantity is requested. Convert all units first. After computing, check the answer against the story (is a negative number of people possible?) and confirm the final line answers the requested quantity, not an intermediate one.
Losing marks on fractions, decimals and percentages by applying procedures without a sense check, for example writing 3/8 as 0.38, or adding fractions by adding numerators and denominators.
The notation invites pattern-matching: 3/8 looks like it should map to 0.38, and 1/2 + 1/3 looks like 2/5. Without a benchmark sense of size, the wrong answer looks tidy and plausible.
What to do instead
Memorise benchmark conversions (1/2, 1/4, 1/3, 1/5, 1/8, 1/10) and estimate before computing: 3/8 is a bit less than a half, so 0.38 is impossible. For fraction arithmetic, always convert to a common denominator in writing rather than manipulating the digits directly.
Spending a long time on one hard non-verbal item, then rushing the rest of the section and leaving later items unanswered.
Non-verbal items are designed to look solvable, so candidates persist. Because the pre-test is strictly timed and adapts in difficulty, one stubborn item can cost several easier marks later in the same section.
What to do instead
Set a personal time cap per item (roughly 40–50 seconds) and rehearse abandoning and moving on. If no pattern appears within the cap, mark a best guess immediately, note it mentally, and return only if time remains. Practise full timed sections so the cap becomes automatic.
On rotation and reflection items, choosing the option that matches the stimulus exactly, or that is a mirror image, when the question requires a rotation.
The eye is drawn to a familiar shape and stops at recognition. Candidates also assume a shape rotated 90 degrees will look 'different' when in fact a symmetric figure can look identical, and they fail to track an asymmetric marker such as a shaded corner or a dot.
What to do instead
Track one asymmetric feature (a shaded square, a protruding arm, a dot) rather than the whole shape. For rotation, physically turn the page or your hand to test the option; for reflection, check that the marker has flipped to the opposite side. Eliminate any option identical to the stimulus when rotation is required.
In verbal reasoning analogy and odd-one-out items, choosing a pair linked by a loose association ('both are animals', 'both are in a kitchen') rather than by the same precise relationship as the example.
Loose association is fast and feels satisfying, and many distractors are deliberately built on shared category membership. Candidates also read the stem as 'which pair goes together' rather than 'which pair relates in the same way as the given pair'.
What to do instead
State the relationship in a full sentence before looking at options ('a glove is worn on a hand as a sock is worn on a foot'). Test each option against that exact sentence and reject any that needs a different wording. For odd-one-out, find a rule that excludes exactly one item, not one that merely groups the others loosely.
In letter-series and code questions, working letter by letter from A=1 without writing the alphabet down, then losing track of position or direction partway through.
Holding alphabet positions in working memory while also tracking a pattern consumes capacity, and candidates confuse 'three places forward' with 'the third letter after'. Reversals (Z to A) and wrap-around at the ends cause silent errors.
What to do instead
Write the alphabet in a line at the start of the section and mark positions as you use them. For each series, write the numeric step between consecutive letters before predicting the next term, and check whether the pattern alternates or changes step size. For codes, decode one word fully and verify it against a second word before applying it.
Leaving answers blank when unsure, or changing a first answer without a concrete reason, in a multiple-choice test with no negative marking.
Candidates carry over habits from school tests where blanks feel safer than wrong answers, and from advice about 'trusting your first instinct' that does not distinguish a genuine second thought from anxiety. On the pre-test, an unanswered item scores zero with certainty, while a reasoned guess has a real chance.
What to do instead
Adopt a firm rule: every item is answered before moving on, with a best guess flagged for review. Only change an answer if you can state the specific error in the original reasoning; otherwise leave it. Rehearse this in timed practice so the rule holds under pressure.