TOK, the Extended Essay and CAS: A Parent’s Guide to the IB Core

2026-06-12
IB Diploma · For Parents

TOK, the Extended Essay and CAS: A Parent's Guide to the IB Core

By GL Academy · 8 min read

IB Diploma students working on the core components at GL Academy in Kuala Lumpur

If your teenager is starting the IB Diploma, you have probably heard three short, slightly mysterious labels: TOK, EE and CAS. Together they make up what the IB calls the "core", and they sit right at the heart of the programme.

This guide explains, in plain language, what each one is, how they affect the final score, and the simple things you can do at home to help. No jargon, no hype — just what a parent actually needs to know.

The big picture: 6 subjects plus the core

An IB Diploma student studies 6 subjects, chosen across different groups. Around those subjects sit the three core components, which develop the independent, reflective thinking that universities value so highly.

Studies of language & literature Language acquisition Individuals & societies The sciences Mathematics The arts THE CORE TOK Extended Essay CAS
Six subjects surround the three-part core, which sits at the centre of every IB Diploma.

TOK: Theory of Knowledge

Theory of Knowledge (TOK, or the study of "how we know things") is a course of around 100 teaching hours that asks one deceptively simple question: how do we know what we know? Students explore this across different areas of knowledge — the sciences, history, the arts, mathematics and more.

TOK is discussion-based rather than exam-based. It is assessed in two parts: a 1,600-word essay on one of several prescribed titles set by the IB, and the TOK exhibition, where students choose 3 real-world objects and explain how they connect to a knowledge question. Many students find it the most surprising and enjoyable part of the Diploma.

If you hear your child say "but how do we actually know that?" at the dinner table, TOK is working. These conversations are exactly what the course is designed to spark.

EE: the Extended Essay

The Extended Essay (EE) is an independent research essay of around 4,000 words on a topic the student chooses themselves, usually within one of their subjects. It takes roughly 40 hours of work, is guided by a supervising teacher, and includes a structured reflection process along the way.

It is the closest thing to undergraduate research that students meet at school, and it is excellent preparation for university. The topic matters: a question your child genuinely cares about makes those 4,000 words far easier to write.

CAS: Creativity, Activity, Service

Creativity, Activity, Service (CAS) is the experiential, learning-by-doing strand of the core. It is built around three areas:

  • Creativity — the arts and creative thinking, from music and drama to designing something new.
  • Activity — physical exertion and a healthy lifestyle, such as sport, dance or hiking.
  • Service — a meaningful, unpaid contribution to others or the community.

CAS also includes a longer CAS project that students plan and carry out over time. Importantly, CAS is not graded — but it is required. A student cannot be awarded the Diploma without completing it satisfactorily.

TOK Theory of Knowledge ~100 hours 1,600-word essay + exhibition (3 objects) How do we know? EE Extended Essay ~4,000 words ~40 hours Student's own topic Independent research CAS Creativity·Activity·Service Experiential learning Includes a CAS project Not graded · required Learning by doing
The three core components at a glance — each develops a different kind of thinker.

How the core affects the final score

This is the part most parents want to understand. Each of the 6 subjects is scored from 1 to 7, giving a maximum of 42 points. TOK and the EE are then assessed together and can add up to 3 bonus points through a simple matrix — bringing the maximum to 45.

A student needs at least 24 points to pass, and the Diploma cannot be awarded without satisfactory CAS, even though CAS itself earns no points.

How the 45 points add up 6 subjects × 7 = 42 points TOK + EE up to +3 Maximum total: 45 points Pass mark: 24 points CAS must be completed to pass
42 from your subjects, up to 3 bonus from TOK and the EE, 45 at the top — and CAS is the gate that must be cleared.

A realistic 2-year timeline

The core runs steadily across the two years of the Diploma. CAS is ongoing throughout, while TOK and the EE build to deadlines in the first term of the second year — a period parents should keep an eye on.

The core across two years Year 1 start Year 1 mid Year 1 end Year 2 term 1 TOK begins CAS starts Choose EE topic EE first draft EE final + TOK essay deadlines CAS continues all the way through — both years The busiest stretch is the first term of Year 2, when EE and TOK deadlines arrive together.
CAS runs throughout; the EE and TOK essay both come to a head early in the second year.

How you can support your child

You do not need to understand TOK or write a single word of the EE to be a brilliant support. What helps most is steady encouragement and a calm home base.

Don't write the EE

The essay must be your child's own work. Ask questions and show interest, but resist the urge to take over.

Help with time management

The core rewards planning. Help your child break big tasks into small weekly steps rather than last-minute sprints.

Encourage reflection

Reflection is built into both the EE and CAS. Asking "what did you learn from that?" reinforces exactly the right habit.

Celebrate CAS

CAS earns no points but builds character. Treat the concert, the match or the volunteering as something to be proud of.

Talk TOK at dinner

Ask what they're discussing in TOK. Real conversations about knowledge and bias are the heart of the course.

Watch the Year 2 crunch

EE and TOK deadlines stack up in the first term of Year 2. A little extra patience at home goes a long way then.

Common worries, answered

Is the Extended Essay really 4,000 words?

Yes, around 4,000 words — but it is built up gradually over many months with a supervisor's guidance, not written in one go. With a topic your child enjoys and a sensible plan, it is very manageable.

Does CAS affect the final score?

CAS earns no points, so it will not raise or lower the number on the certificate. However, it is compulsory: the Diploma cannot be awarded unless CAS is completed satisfactorily.

What if my child struggles with TOK?

TOK is a new way of thinking, so a slow start is normal. It improves quickly with discussion and practice, and a good teacher or coach can make the abstract ideas click. It is rarely the part that decides a result.

How many points does the core add?

TOK and the EE together contribute up to 3 bonus points, taking the maximum from 42 to 45. CAS adds no points but must be completed to earn the Diploma.

How does GL Academy help?

GL Academy offers structured IB coaching, including dedicated support for the Extended Essay and TOK, plus help with internal assessments across subjects. We focus on steady progress, good planning and genuine understanding rather than last-minute cramming.

Supporting your child through the IB core

GL Academy in Kuala Lumpur is British Council accredited and offers focused IB coaching, including EE and TOK support and internal-assessment help. Explore the programme and see how we can help your child thrive.

Explore the IB Diploma Programme