Why international schools test at all
The official reason a school tests applicants is to confirm placement and identify support needs. The fuller reason is that international schools admit children from forty or fifty different education systems with no common reporting standard. The Singaporean school report and the French school report do not measure the same thing in the same way, and neither maps neatly onto the British or IB curriculum the receiving school runs. A short standardised assessment provides a common reference point. It does not determine the admissions decision in isolation, but it shapes the cohort and informs streaming, setting and learning support from the first day.
The good news for families is that no major international school admission test rewards drilling in the way a competitive grammar-school examination does. The tests are designed to measure underlying reasoning rather than learnt content. The bad news is that "reasoning" is harder to prepare for than "facts", and many of the published preparation resources do more to unsettle children than to help them.
CAT4: the most common entry test
The Cognitive Abilities Test, fourth edition, is the most widely used international school admission test in the world. Almost every British-curriculum international school uses it. A large number of IB schools use it as a baseline. American schools increasingly accept CAT4 results in addition to MAP. The test is published by GL Assessment, takes ninety minutes in total split across four short batteries, and is normally administered online at the school or remotely.
The four batteries are verbal reasoning, quantitative reasoning, non-verbal reasoning and spatial reasoning. Each is reported on a standard age-normed scale. Schools receive a profile that shows the child’s position relative to the international cohort and the balance between the four areas. A child strong on non-verbal and spatial but weaker on verbal is a familiar profile, often a recent EAL learner, and the school can plan accordingly. Read our piece on CAT4 explained for parents for the test design detail.
Schools use CAT4 results to set expected attainment bands, to identify students likely to need stretch, and to flag students likely to need support. The result is not the basis for accepting or rejecting an applicant in most cases, although it can be decisive at heavily oversubscribed Tier 1 schools where the admissions team is choosing between several broadly qualified applicants.
Comparing schools by admissions test type?
Our compare schools tool shows which entry assessment each school uses, the length of the test, and whether it can be sat remotely. Useful at the shortlist stage so families do not face four different tests in three weeks.
MAP: the American alternative
The Measures of Academic Progress, published by NWEA, is the standard assessment at American-curriculum international schools and a growing number of dual-curriculum schools. Unlike CAT4, MAP is adaptive: the test adjusts difficulty as the child answers, producing a precise reading and mathematics RIT score that schools can compare across grade levels and across years. MAP measures attainment rather than reasoning, which makes it a closer cousin of conventional achievement testing than CAT4.
Schools use MAP both as an admissions assessment and as a termly progress measure for enrolled students. For applicants, MAP scores in reading and mathematics give the school a quick read on grade-level placement, particularly useful when a child arrives mid-year from a different curriculum. Read our MAP test piece for the deeper guide.
ISA and ACER tests
The International Schools’ Assessment, run by the Australian Council for Educational Research, is used by a smaller but significant number of international schools, particularly those drawing on the Australian and IB Primary Years Programme tradition. It measures reading, writing and mathematical literacy with content drawn from across the international school curriculum, and it is age-normed against the cohort of international schools using the test. Schools that use ISA tend to use it consistently rather than introducing it for one-off admissions decisions. Some schools use both ISA and CAT4.
ACER also produces an entry-screening assessment used by some schools alongside or in place of the published cognitive batteries. The differences are technical rather than dramatic. Our ISA piece covers the practical detail.
Primary entry: the play-based and observational approach
For children entering at age 3 to 6, formal testing is rare. Schools use observational assessments instead: a forty-minute structured play session in which the admissions team observes language, motor skills, social interaction and willingness to engage with adult-directed tasks. Some schools also use the BAS or WPPSI batteries for borderline placement decisions, although these are normally administered by an educational psychologist rather than the admissions team.
The implication for parents is that there is essentially no preparation to do beyond ensuring the child is rested, comfortable and familiar with the idea of meeting new adults. Families who arrive at an early-years admissions session with a coached child often perform less well than those who arrive with a relaxed one. Read our piece on admissions at age 3 and 4 for more on this stage.
How schools actually use the results
Across all four test families, schools use the results in three ways. First, as a confirmation that the child is broadly within the school’s academic range. A child whose profile sits significantly above or below the cohort raises a flag for further discussion, usually a conversation with the parents rather than an automatic decision. Second, as a placement tool. The result helps the school decide year group, setting or streaming, and language support. Third, as a baseline. The school will retest in later years and look at progress against the initial result.
What the results do not normally do is decide acceptance in a vacuum. A child with an average CAT4 profile applying to a Tier 1 academic school may still be admitted if the parent interview, the reference and the school report support the application. Equally, a child with a strong CAT4 profile is not guaranteed a place if the year group is full or the cohort is unbalanced. The test is one input. Read our admissions process overview for how the inputs fit together.
What helpful preparation looks like
The most useful preparation is familiarity rather than coaching. Show the child what the test interface looks like, two or three practice questions per battery, an explanation of the timing, and a conversation about doing best work without panic. Free sample materials are available from GL Assessment, NWEA and ACER. An hour spread across two evenings is enough.
Beyond familiarity, attend to the basics. A well-rested child performs noticeably better. A child taking the test in an unfamiliar language should sit it at their best time of day. A child anxious about a new school should visit the campus before the assessment where possible. None of this changes the underlying ability, but all of it reduces the gap between the child’s ability and what the test measures on the day.
If your child has identified additional needs, request access arrangements in advance. Most schools offer extra time, a separate room, or other adjustments where the need is documented. Submit the documentation with the application so the school has time to plan. Read our piece on neurodivergent international school choice for the broader picture.
Over-preparation and the schools that detect it
A small industry of test-preparation tutors targets international school admissions. Their efficacy varies. Schools running CAT4 do flag suspicious result patterns: very high quantitative reasoning paired with very low verbal reasoning in a non-EAL child, for example, or score profiles that improve dramatically between attempts. Some schools require a retest under supervision if the profile looks coached. The result can be an admissions outcome materially worse than the unprepared performance would have produced.
The honest position is that ninety minutes of practice produces minor familiarity gains. Twenty hours of drill produces detectable distortion. Parents who feel pressured to invest heavily in test preparation are usually better served by investing the same effort in the parent interview, the documents pack, and the choice of schools to apply to. Read our interview preparation guide for the parts that respond more to thoughtful preparation.
Where families do see meaningful gains from preparation is on test-taking habits rather than on content. Reading the question carefully, eliminating obviously wrong answers before guessing, not lingering on a single hard item, pacing across the four batteries: these are durable skills that transfer to all future assessment. A handful of timed practice runs at home, in normal conditions, with the child in charge of pacing, will produce more reliable improvement than any volume of content drill.
There is also a wider question of what we are optimising for. A place at a Tier 1 school secured by an unrealistically prepared score is not, on balance, a good outcome for the child. The school will set the child in a stream above the child’s actual range, the child will struggle, the family will eventually move them down. Honest assessment serves the family. Assessment gamed serves nobody.
Frequently asked questions
Can my child sit the admissions test remotely? Most schools allow remote sitting with proctoring software, particularly for families applying from abroad. Confirm with the registrar at the point of application.
How long are the results valid? CAT4 and MAP scores are typically considered current for twelve to eighteen months. Older results may be accepted but the school often retests.
Does my child need to pass the test? The tests are not pass-fail. They produce a profile. A profile outside the school’s typical band triggers a conversation, not an automatic rejection.
Will the school share the results with us? Most schools provide a summary report to parents after enrolment. Pre-offer, schools sometimes share results and sometimes do not. Ask politely; the answer is school-specific.