CAT4 and Entrance Tests for International Schools in Thailand

Families often arrive expecting one recognisable “international school entrance exam” that works across Thailand. That is not how admissions is organised. Each school sets its own process, and the same school may use different methods for different ages or year levels. A friend’s experience with a Year 8 applicant can therefore be a poor guide to what will happen with a child entering Reception or Year 3.

For younger children, the school may learn more from a classroom visit, play-based observation or trial session than from a formal paper. International School Eastern Seaboard, for example, publishes a free trial day for PreK–Grade 1 applicants, while older applicants face a different set of requirements. As students get older, schools are more likely to introduce structured academic tasks, subject-specific testing or an interview because placement has to make sense within a more defined curriculum.

Language can add another layer. A student with strong reports from a previous school may still need English-language screening to establish whether they can access the curriculum comfortably or would benefit from EAL support. Where a child has documented learning or support needs, the admissions process may also be used to judge whether the school has the staffing and resources to meet them.

Schools rarely look at one score in isolation. NIST, for instance, says it considers age and year level, space availability, English proficiency, previous records and academic ability before and alongside the assessment stage. That distinction matters: a strong assessment cannot create a seat in a full year group, and a request for further information is not the same thing as a failed test.

CAT4 stands for the Cognitive Abilities Test, Fourth Edition. It is a standardised assessment of reasoning, not a check on whether a child has mastered a particular textbook or syllabus. GL Assessment divides the test into four batteries: verbal, quantitative, non-verbal and spatial reasoning. Together, they are intended to show how a student approaches different kinds of information.

Verbal reasoning uses words and relationships between concepts. Quantitative reasoning focuses on patterns and problem-solving with numbers. Non-verbal tasks rely on pictures and diagrams, while spatial reasoning asks students to manipulate shapes or visual information mentally. These are not four school subjects. A child who is comfortable with familiar maths exercises may still show a different profile when the task is about recognising a numerical relationship without applying a rehearsed classroom method.

That is why CAT4 should not be read as an English test or a maths attainment test. It does not establish whether a student has covered a particular writing convention, algebra topic or reading curriculum. A school that needs that information may add its own English, writing or maths task. Other schools may use CAT4 for admissions, placement, support planning or simply as one part of a broader evidence set.

CAT4 reporting can include Standard Age Scores (SAS) for each battery and an overall mean. Parents sometimes take that format to mean there must be a universal admissions cutoff. There is not. Schools decide for themselves whether to use CAT4 and how much weight to give it, so a score quoted by a tutoring website or another family should not be treated as a Thailand-wide pass mark.

The test publisher is unusually clear on preparation. GL Assessment strongly advises against practising CAT4-style questions in advance because training can affect the reliability of the score as a measure of reasoning. Helping a child understand that the session is timed, that there will be instructions and that unfamiliar-looking questions are normal is different from drilling patterns until the format becomes memorised.

Even at a school that uses CAT4, the cognitive profile may answer only one part of the admissions question. If the concern is whether a student can learn comfortably in English, a separate language assessment is more relevant. International School Bangkok, for example, requires an English proficiency assessment for K–Grade 12 applicants who may not yet be proficient at grade level and may request additional standardised, maths or learning-support assessments depending on the learner profile.

An English proficiency assessment is also different from a school-set writing task. The first may be designed to establish whether a student can understand classroom language and participate in learning; the second can show reading comprehension, written expression and age-appropriate academic literacy. A child can sound fluent socially yet be unfamiliar with extended academic writing, while another may write accurately but need more confidence in spoken interaction.

A maths or grade-level task is usually closer to an attainment check. It can reveal whether the student’s previous curriculum has covered the material expected in the intended class. A gap is not automatically evidence of low ability. International curricula sequence topics differently, so admissions staff may be trying to distinguish a teachable curriculum gap from a broader placement issue.

Interviews serve a different purpose again. With older students, schools may explore motivation, communication, subject choices and how the student thinks about their own learning. Some processes involve parents as well. Harrow Bangkok describes an academic assessment plus an interview, while ISB publishes separate virtual interview arrangements for parents of younger applicants and for middle- and high-school students themselves.

For younger children, a play-based observation or trial day can be more informative than a formal written paper. Schools may watch how a child joins a group, follows age-appropriate instructions and copes with the environment. None of these components should be assumed to be standard across Thailand; the relevant question is what the chosen school uses for the child’s actual age and entry point.

Admissions teams are not simply trying to decide whether a child produced a “high enough” number. They need to know whether the proposed year level is appropriate, whether the student can access teaching in English and whether any extra support can realistically be provided from the start. The meaning of a test result changes when it is read alongside school reports, recommendations and the student’s previous curriculum.

If the assessment and the existing records tell different stories, a school may ask for more evidence, another conversation or an additional task. That can be particularly relevant for a recently relocated multilingual child whose verbal performance needs to be read in the context of language exposure. A CAT4 profile is evidence for a school decision; it is not a diagnosis or a permanent verdict on a child’s ability.

Support capacity is another part of the decision. International School Eastern Seaboard explicitly says it assesses whether it can provide the level of care and support a student requires. With older applicants, schools may also look at readiness for chosen subjects or a pathway such as the IB Diploma, IGCSE or A levels where those programmes apply.

One factor sits completely outside the test: space. Both NIST and ISB publish admissions information that treats year-group or cohort capacity as part of the decision. A qualified student can therefore face a wait pool because no seat is available. That is an availability problem, not evidence that the child “failed” the assessment.

The most useful preparation starts with the school, not with a generic CAT4 preparation package. “Assessment” can mean a cognitive test, a school-set writing task, maths, English proficiency, an interview, or several components on different days. Until the family knows the exact format for the child’s year level, it is easy to spend time practising the wrong thing.

CAT4 is the clearest case where more practice is not necessarily better. GL Assessment strongly advises against training on CAT4-style questions beforehand because practice can change the reliability of the score. The assessment is meant to capture reasoning, not familiarity with a bank of rehearsed patterns. A child can still be prepared for the experience: they can know that the session is timed, that instructions and examples come first, and that some questions are designed to feel unfamiliar.

School-set English, writing and maths tasks deserve a different kind of preparation. Lightly returning to normal grade-level work can help after a long holiday or a disruptive move: reading instructions in English, writing a coherent response, working comfortably under a time limit, and revisiting maths topics the student has already learned. Trying to compress an unfamiliar curriculum into a few days is more likely to raise anxiety than produce a useful picture of the student.

For an interview, rehearsing polished speeches is usually less helpful than making sure the child can talk naturally about school, interests and areas they find difficult. Older students may also need to discuss subject choices or goals. Admissions staff are trying to hear how the student communicates and reflects, so a parent-written answer delivered from memory can obscure the very thing the interview is meant to reveal.

Basic logistics matter because tiredness and technical stress can distort the day. A normal sleep routine, food beforehand and an unhurried arrival are more useful than a final morning drill. For an online session, the device, browser, camera, headphones and connection should be tested before the appointment rather than during the first few minutes of the assessment.

Families should also disclose relevant EAL, learning-support or medical documentation when the school asks for it. The purpose is not to weaken the application; it allows the school to decide what accommodations are appropriate and whether it can meet the student’s needs. No amount of preparation can guarantee an offer, because the final decision may also depend on previous records, support capacity and available places.

Assessment day can be one visit to campus, a remote test from home, or a process split across separate testing and interview appointments. ISB states that assessments can be conducted on-site or online; NIST allows certain elementary assessments online for applicants outside Bangkok; Harrow Bangkok also publishes both online and campus options. Those examples show the range of practice, not a Thailand-wide entitlement to remote testing.

There is no useful universal duration to plan around. CAT4 has its own age-dependent timing, but a school may add English, maths, writing, an interview or a break. The practical question is how long the school wants the family to reserve for the entire appointment and whether the session is divided into separate blocks.

Remote assessments can come with school-specific requirements for the device, browser, camera, headphones and adult supervision. Parents should not assume they are allowed to sit beside the child or explain questions. For an on-campus appointment, identification, glasses or previous documents should be brought when the school asks for them, rather than from a generic internet checklist.

Illness, travel disruption or a missed appointment is another policy question for the individual admissions office. Families applying from overseas should confirm remote options before making plans, since one school’s online arrangement says nothing about another school’s process.

The result of an admissions assessment is not always a simple pass-or-fail message. Depending on the school, a family might receive an offer, enter a wait pool, be asked for more documentation, complete further assessment, or discuss EAL or learning support. Those are examples of possible outcomes, not a standard status system shared by international schools across Thailand.

Parents may not receive the same report that the school sees. CAT4 can produce detailed numerical data and a reasoning profile, but each school decides what it shares with families. It is worth knowing whether the school provides a numerical report, a short feedback conversation or only the admissions decision. A lack of score sheets does not mean the assessment was ignored.

A weaker part of the profile also needs context. A recently relocated multilingual student may show a less confident verbal result while school reports still demonstrate strong learning over time. Admissions teams can compare those sources rather than treating one sitting as a complete portrait. If the decision is surprising, parents can ask whether the school’s policy allows feedback, without assuming the reason in advance.

Space and performance should be kept separate. ISB, for example, publishes a wait-pool route for qualified applicants when there is no opening at the relevant grade level or within required support services. A family can therefore leave the process without an immediate place even though the child has not “failed” the assessment.