ISEB Common Pre-Test Guide for Parents

The ISEB Common Pre-Test is a set of online adaptive assessments administered by the Independent Schools Examination Board. It is used by independent senior schools to assess pupils for Year 7 or deferred Year 9 entry.

Children usually sit the test in Year 6 or Year 7. The results are shared electronically with every school applied to, so a child sits the test once per academic year rather than sitting separate tests for each school.

The test is adaptive. This means the difficulty of questions changes according to the child's answers. If a child answers correctly, the system presents harder questions. If a child answers incorrectly, the system may lower the difficulty. This is why the ISEB is fundamentally different from an ordinary school test, because accuracy, timing, and decision-making all matter in ways they do not in a standard paper exam.

Children may take all four sections on the same day or split them across days, depending on the school's arrangements. Pencil and paper are permitted throughout all sections. The full testing time is approximately 2 hours 15 minutes.

The ISEB is not only a knowledge test. The format itself creates pressure that does not exist in a standard school exam. Three constraints are especially important for preparation:

The system calibrates question difficulty in real time. A correct answer triggers a harder question, which carries a higher score weighting. An incorrect answer triggers an easier question with lower weighting. Two children with the same number of correct answers can receive different scores if one reached harder questions before making errors.

Each submitted answer is locked immediately. The next question does not appear until an answer is selected. There is no review screen at the end. This is a structural requirement of the adaptive algorithm, as the system needs each answer before it can determine the next question's difficulty.

The test is taken entirely on screen. Children must read, calculate and answer under time pressure without the cues, such as underlining, margin notes, and visual scanning, that paper allows. Familiarity with screen-based work before the real test reduces the cognitive load of the format itself.

There is no single hardest section for every child. The difficulty depends on school background, vocabulary, reasoning experience, reading habits and confidence under time pressure. However, some patterns are consistent.

Many children do not encounter this kind of thinking in normal school lessons. The challenge is not curriculum knowledge; rather, it is pattern recognition under time pressure without language cues.

• Visual sequences and matrices
• Shape rotation and spatial patterns
• 2D and 3D reasoning "How many cubes" questions (added 2022)

This section is difficult when a child understands the logic but fails because one or two key words are unfamiliar. It can be especially hard for children who read less or whose English vocabulary is still developing.

• Synonyms, antonyms and analogies
• Word codes and letter sequences
• Verbal logic problems

The Maths section is based on the Year 5 curriculum. It becomes difficult when core topics are not secure. In an adaptive test, errors in easier questions are particularly costly, because they reduce the difficulty path, which reduces the maximum score available.

• Fractions, decimals, percentages and ratio
• Geometry and statistics
• Multi-step word problem

English is difficult for children who read too quickly, miss detail, or answer from general impression rather than the text. Since 2022 it produces two separate scores for comprehension and SPaG, so both areas need attention.

• Reading comprehension and inference
• Vocabulary in context
• Spelling, punctuation and grammar

1. Diagnose first to identify the child's weakest area before starting preparation.
2. Fix Maths and English gaps, which are curriculum-based and can improve with focused, targeted work.
3. Introduce Verbal and Non-Verbal Reasoning early, as these need repeated exposure and do not respond as quickly to cramming.
4. Move to online timed practice, especially because the real test is digital and adaptive.

The questions below are original TestPrep-Online questions illustrating the type of thinking required in each section. They are not official ISEB questions and do not come from the ISEB question bank.

The ISEB does not report raw marks or percentages. Each subject produces a Standardised Age Score (SAS). The algorithm that generates the SAS weights three inputs:

• Input 1: Correct answers, which is the total number of correct responses.

• Input 2: Difficulty reached, which is a function of how far the adaptive path progressed.

• Input 3: Age at sitting, using the exact age in years and months.

• Output: SAS =age-adjusted standardised score per subject.

Schools receive per-subject SAS, not a single composite mark.

Because the SAS weights the difficulty level reached, and not only how many answers were correct, two children with the same number of correct answers can receive different scores. The child who reached harder questions before making errors scores higher.

The age adjustment means a child sitting in October (younger in their year group) is not disadvantaged against a child sitting in February. The algorithm corrects for exact age in months.

Schools receive a report showing each subject's SAS alongside a percentile rank. There is no universal pass mark. Most highly selective schools look for performance in approximately the top 15-20% nationally. Each school sets its own threshold and weights subjects independently; therefore, you should confirm requirements directly with target schools.

Many parents search for ISEB past papers. There are no publicly available official ISEB past papers, because the content bank is updated regularly and the adaptive format means no two children see the same paper.

Practice papers described as "ISEB past papers" are approximations of the question types. They are useful for content familiarisation but do not replicate two critical features of the real test:

• Adaptive difficulty scaling, since a printed paper presents questions at a fixed difficulty. It cannot show which difficulty band the child is in, nor replicate the progression from easier to harder questions that occurs when the child performs well.

• One-way navigation, because on paper, children can skip, mark and return. This creates a habit that does not exist in the real ISEB environment.

Paper practice is not worthless, as question-type recognition transfers to the real test. But the final 4-6 weeks of preparation should use online tests with locked answers and timed conditions, to build the decision-making habits the actual system requires.

• 01 | Understand the format before anything else. Parents and children should understand the four sections, the timing, the adaptive format and the fact that answers cannot be revisited. A child who is surprised by the no-back-button constraint on test day is at a disadvantage before the first question.

• 02 | Run a diagnostic test to identify weak areas. A child may be strong at school but still struggle with Verbal or Non-Verbal Reasoning. A diagnostic test across all four sections identifies the actual starting point, not the assumed one.

• 03 | Close Maths and English curriculum gaps first. Reasoning scores are harder to move quickly. Curriculum-based gaps in fractions, punctuation, and grammar can be closed in a defined number of hours. Address these before reasoning practice begins.

• 04 | Introduce reasoning question types one at a time. Verbal and Non-Verbal Reasoning each contain multiple distinct question types. Children who encounter all types simultaneously make slower progress than those who master each type before moving to the next. Short sessions three to four times per week produce better retention than infrequent long sessions.

• 05 | Switch to timed, locked-answer practice 6 weeks before the exam. From this point, all practice should replicate ISEB conditions: timed per section, no ability to change a submitted answer, and no skipping. The purpose is to build the habit of committing to an answer under time pressure, which is the most transferable skill from practice to the real test.

• Guardian Portal registration opens: 9 June 2026

• Live testing begins: 1 September 2026

• Testing session ends: Late May 2027

Each senior school sets its own internal deadline for registration. Always confirm the exact deadline directly with the schools you are applying to, because school deadlines are often earlier than the ISEB session closing date.

Over 160 independent schools accept ISEB results. Schools that consistently include the ISEB as part of their admissions process include:

• Eton College, Winchester College, Harrow School

• Wycombe Abbey, Cheltenham Ladies' College, Benenden School

• Rugby School, Marlborough College, Charterhouse

• Radley College, St Paul's School, Tonbridge School, Wellington College

The complete and current list is maintained on the ISEB website. Requirements vary by school and admissions route, so always check directly.