Quest Assessment vs ISEB Common Pre-Test: Which Schools Use Which?

Quest Assessment and the ISEB Common Pre-Test are the two leading adaptive computer-based admissions assessments used by selective independent schools in the UK. They look similar on the surface — both are online, both adapt to each child's ability level, and both cover English, Mathematics, Verbal Reasoning, and Non-Verbal Reasoning. But they exist for fundamentally different purposes, are used by different schools for different admissions stages, and require meaningfully different preparation strategies.

This guide clarifies which schools use Quest, which use ISEB, what the substantive differences are in format, content, timing, and scoring, and how families should approach preparation when targeting both assessments in the same academic year. For specialist tuition covering either or both assessments, visit our Quest Assessment preparation page or our ISEB Common Pre-Test preparation page.

The Fundamental Difference: Year 7 vs Year 9 Entry

The single most important distinction is the admissions stage each test serves.

Quest Assessment is used for 11+ entry to Year 7 at selective independent schools. Children typically sit Quest in October or November of Year 6, for entry to senior school the following September. The result informs whether a child is invited to the next stage of the school's admissions process, which may include an interview, group activity, or written assessment.

ISEB Common Pre-Test is used as a pre-selection filter for 13+ entry to Year 9 at leading boarding and day schools. Children typically sit it in November or January of Year 6, but the entry they are being pre-selected for is two years later — in September of Year 8. A child who passes the ISEB pre-test receives a conditional offer: they are offered a place subject to sitting and passing the school's main exam (usually Common Entrance) in Year 8.

This means that a Year 6 child might sit both Quest and ISEB in the same autumn term: Quest for 11+ (Year 7) entry at independent day schools, and ISEB for 13+ (Year 9) pre-selection at boarding schools. This is a common situation in South-East England, where families often want to keep options open across both entry routes.

Which Schools Use Quest Assessment vs ISEB?

The lists below show representative schools for each assessment. They are not exhaustive — always verify with each individual school.

Assessment	Entry Stage	Example Schools	School Type
Quest	11+ (Year 7)	Dulwich College, City of London Girls, Forest School, Haberdashers' Boys/Girls, Whitgift, Trinity Croydon, The Perse, Cheltenham Ladies', Oxford High, Surbiton High	Independent day schools (primarily)
ISEB	13+ (Year 9)	Eton College, Harrow School, Winchester College, Charterhouse, Rugby School, Marlborough College, Radley College, Oundle School, Sevenoaks School, Wellington College	Leading boarding and day schools

Note that some schools offer entry at both Year 7 and Year 9, and may use Quest for Year 7 entry and ISEB for Year 9 pre-selection. Sevenoaks School, for example, uses ISEB for 13+ pre-selection. Families targeting multiple entry routes across different schools may find themselves preparing children for both assessments in the same academic year.

Format Comparison: Quest Part 1 vs ISEB Common Pre-Test

Feature	Quest Assessment Part 1	ISEB Common Pre-Test
Purpose	11+ entry (Year 7) at independent schools	13+ pre-selection (Year 9) at boarding/day schools
Administered by	Quest Admissions	ISEB (Independent Schools Examinations Board)
Format	Online, computer-based	Online, computer-based
Sections	English (non-adaptive), Maths (adaptive), NVR (adaptive), VR (adaptive)	English (adaptive), Maths (adaptive), VR (adaptive), NVR (adaptive)
Duration	Approx. 70 minutes (varies by school)	Approx. 60–80 minutes (varies by school)
Adaptivity	English non-adaptive, other 3 sections adaptive	All four sections adaptive
Scoring	Standardised Age Score (SAS)	Standardised Age Score (SAS)
Registration	Register directly with each target school	Register with each target school; school registers child with ISEB
Where sat	At home or at target school (school-dependent)	At child's current school (if registered centre) or at target school
Typical timing	October–November Year 6	November–January Year 6

The Key Structural Difference: English Adaptivity

The most significant structural difference between the two tests is in how the English section works.

In Quest Part 1, the English section is non-adaptive: all candidates see the same questions in the same order, and children can move backwards and forwards between questions freely within the time limit. This allows children to use strategic approaches such as answering easier questions first and returning to harder ones.

In the ISEB Common Pre-Test, the English section is adaptive: question difficulty adjusts in real time based on each submitted answer, and children cannot return to previous questions. This is the same dynamic as Quest's Maths, NVR, and VR sections.

This difference has a direct implication for exam strategy: a child practising for Quest needs to understand two distinct approaches (non-adaptive for English, adaptive for Maths/NVR/VR), while a child practising for ISEB needs the same adaptive strategy applied consistently across all four sections.

Content Overlap: What Preparation Is Shared

Despite the differences in purpose and format, the subject content of both tests overlaps substantially. Both Quest and ISEB test children on:

English: Reading comprehension, inference and deduction, vocabulary in context, identifying literary devices, understanding writer's purpose and technique. In some Quest configurations, SPAG (Spelling, Punctuation, Grammar) is also included in the English module.

Mathematics: The core KS2 national curriculum topics through to approximately Year 5 or Year 6 level, including number and place value, the four operations, fractions and percentages, measurement, geometry, and data interpretation. The ISEB Maths section is generally considered to be at a slightly higher curriculum level than Quest Maths, reflecting the two-year age difference between the typical Quest candidate (10–11) and the typical ISEB candidate (10–11 sitting for a Year 9 place).

Non-Verbal Reasoning: Pattern recognition, shape sequences, spatial reasoning, matrices, odd-one-out questions, and rotations and reflections.

Verbal Reasoning: Word analogies, letter codes, sequences, find the word, hidden words, and language logic tasks.

Because the content overlaps so significantly, a child preparing for one test will build skills directly applicable to the other. The preparation can be largely integrated — with specific attention to format differences (particularly the adaptive vs non-adaptive English section) and to the ISEB's generally higher Maths curriculum demand.

Schools That Use ISEB: A Closer Look at 13+ Pre-Selection

The ISEB Common Pre-Test is used by over 70 schools, predominantly highly selective boarding schools. Notable examples include:

Leading boarding schools: Eton College, Harrow School, Winchester College, Charterhouse, Rugby School, Marlborough College, Radley College, Oundle School, Uppingham School, Stowe School, Shrewsbury School, Wellington College, Sherborne School, and Wycombe Abbey. See our full range of 13+ school preparation guides for detailed information on each school's admissions process.

Leading day and mixed schools: Sevenoaks School, Tonbridge School, and others that offer 13+ entry alongside 11+ entry.

The ISEB pre-test result is shared directly between ISEB and the schools a child has registered for. A single sitting covers all schools registered, which means a poor performance on one sitting affects the shortlist at every registered school simultaneously — unlike Quest, where each school's test is technically separate.

Scoring: How Quest SAS and ISEB SAS Compare

Both Quest and ISEB use a Standardised Age Score (SAS) system. Raw scores are adjusted for the child's exact age in years and months at the time of sitting, ensuring that younger children in the same cohort are not systematically disadvantaged.

In both systems, an SAS of 100 represents average performance for a child of that exact age. Neither Quest nor ISEB publishes the SAS thresholds that individual schools use for shortlisting. Schools use the scores alongside other information (teacher reports, interview performance, subsequent written assessments) to make admissions decisions.

One important difference: in the ISEB system, a child's pre-test result is shared automatically with all schools they have registered for. In the Quest system, Quest Part 1 results are shared with each school individually — a child who sits the Quest test for Dulwich College and for The Perse School effectively sits two separate assessments, potentially at different times, rather than one centralised sitting.

When to Start Preparing, and How to Manage Both in Year 6

Families targeting both Year 7 (Quest) and Year 9 (ISEB) entry from the same child's Year 6 need to plan their preparation carefully. The most effective approach is an integrated programme that builds common skills (Maths depth, VR and NVR fluency, reading comprehension breadth) from September of Year 5 onwards, then diverges in the final 8–12 weeks before each test to address format-specific practice.

Key calendar points for Year 6 families managing both: Quest tests typically run in October and November of Year 6; ISEB tests typically run in November and January of Year 6. This means the two test windows overlap substantially. The most selective schools in both systems are competing for the same pool of academically strong Year 6 children, and preparation that begins only in Year 6 is significantly less effective than preparation that builds progressively from Year 5.

Frequently Asked Questions: Quest vs ISEB