As a thoughtful and purposeful inquiry into different ways of knowing, and into different kinds of knowledge, TOK is composed almost entirely of questions.

The most central of these is "How do we know?", while other questions include:

• What counts as evidence for X?

• How do we judge which is the best model of Y?

• What does theory Z mean in the real world?

Through discussions of these and other questions, students gain greater awareness of their personal and ideological assumptions, as well as developing an appreciation of the diversity and richness of cultural perspectives

TOK aims to make students aware of the interpretative nature of knowledge, including personal ideological biases – whether these biases are retained, revised or rejected.

It offers students and their teachers the opportunity to:

• reflect critically on diverse ways of knowing and on areas of knowledge

• consider the role and nature of knowledge in their own culture, in the cultures of others and in the wider world.

In addition, TOK prompts students to: 

• be aware of themselves as thinkers, encouraging them to become more acquainted with the complexity of knowledge

• recognize the need to act responsibly in an increasingly interconnected but uncertain world. 

TOK also provides coherence for the student, by linking academic subject areas as well as transcending them.

It therefore demonstrates the ways in which the student can apply their knowledge with greater awareness and credibility.

Creativity, activity, service (CAS) is one of the three essential elements that every student must complete as part of the Diploma Programme (DP).

Studied throughout the Diploma Programme, CAS involves students in a range of activities alongside their academic studies.

It is not formally assessed. However, students reflect on their CAS experiences as part of the DP, and provide evidence of achieving the seven learning outcomes for CAS.

The three strands of CAS, which are often interwoven with particular activities, are characterized as follows:

• Creativity – arts, and other experiences that involve creative thinking.

• Activity – physical exertion contributing to a healthy lifestyle, complementing academic work elsewhere in the DP.

• Service – an unpaid and voluntary exchange that has a learning benefit for the student. The rights, dignity and autonomy of all those involved are respected.

In order to demonstrate these concepts, students are required to undertake a CAS project. The project challenges students to:

• show initiative

• demonstrate perseverance

• develop skills such as collaboration, problem solving and decision making.

CAS enables students to enhance their personal and interpersonal development by learning through experience.

It provides opportunities for self-determination and collaboration with others, fostering a sense of accomplishment and enjoyment from their work.

At the same time, CAS is an important counterbalance to the academic pressures of the DP.

A good CAS programme should be both challenging and enjoyable – a personal journey of self‑discovery.

Each student has a different starting point, and therefore different goals and needs, but for many their CAS activities include experiences that are profound and life‑changing.

CAS is a component of the DP core.

The extended essay is a required component of the International Baccalaureate® (IB) Diploma Programme (DP). 

It is an independent piece of research, culminating with a 4,000-word paper.

The extended essay provides:

• practical preparation for undergraduate research

• an opportunity for students to investigate a topic of personal interest to them, which relates to one of the student's six DP subjects, or takes the interdisciplinary approach of a World Studies extended essay.

Through the research process for the extended essay, students develop skills in:

• formulating an appropriate research question

• engaging in a personal exploration of the topic

• communicating ideas

• developing an argument. 

Participation in this process develops the capacity to analyse, synthesize and evaluate knowledge.

An extended essay can also be undertaken in world studies, where students carry out an in-depth interdisciplinary study of an issue of contemporary global significance, across two IB diploma disciplines.

Students are supported throughout the process of researching and writing the extended essay, with advice and guidance from a supervisor who is usually a teacher at the school.

Students are required to have three mandatory reflection sessions with their supervisors. The final session, a concluding interview, is also known as viva voce.

The extended essay and reflection sessions can be a valuable stimulus for discussion in countries where interviews are required prior to acceptance for employment or for a place at university.

All extended essays are externally assessed by examiners appointed by the IB. They are marked on a scale from 0 to 34.

The score a student receives relates to a band. The bands are:

• A – work of an excellent standard.

• B – work of a good standard.

• C –work of a satisfactory standard.

• D – work of a mediocre standard.

• E – work of an elementary standard.