The 6 IB PYP Transdisciplinary Themes Explained

The six IB PYP transdisciplinary themes are broad lenses that organise a school's Programme of Inquiry: Who we are; Where we are in place and time; How we express ourselves; How the world works; How we organise ourselves; and Sharing the planet. Teachers use them to connect worthwhile human questions with secure subject knowledge, purposeful inquiry and evidence of learning.

For leaders, the themes provide a whole-school map. For teachers, they help turn curriculum content into coherent units. A theme is not a topic list and it does not remove the need for explicit subject teaching. The current International Baccalaureate guide and Primary Years Programme overview are useful starting points for teams new to the framework.

Consider a Year 4 Sharing the planet unit about water. Learners can measure school water use in maths, investigate filtration in science and write a proposal in English. Each subject contributes something necessary. Long division, spelling or another objective without an authentic connection can still be taught separately.

What the Six PYP Transdisciplinary Themes Mean

The themes describe significant areas of shared human experience through which PYP schools plan inquiry. They are broad enough to recur across ages and contexts, but each unit still needs a precise central idea, selected subject content and clear assessment evidence. The official PYP framework remains the governing source for how schools use them (International Baccalaureate, 2026).

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Who we are

Plain-language meaning: This theme helps learners explore identity, relationships, wellbeing, beliefs, rights and responsibilities. It can include personal development, family and community, but it should move beyond autobiography. The strongest units ask how identity is shaped and how choices affect ourselves and other people.

Classroom example: A Year 3 class investigates how belonging is expressed in different communities. Learners interview a trusted adult, examine a local celebration and map the languages used by the class. In English they compare accounts; in geography they locate connections; in art they study symbols. The final explanation identifies both shared patterns and meaningful differences.

Planning caution: Do not reduce the theme to family trees, feelings worksheets or a display of flags. Protect privacy, avoid asking learners to disclose sensitive family information and ensure that no single family structure, language or cultural viewpoint is treated as normal for everyone.

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Where we are in place and time

Plain-language meaning: This theme explores histories, places, journeys, discoveries and the relationships between people and environments over time. Learners use evidence to explain continuity, change, cause and consequence rather than simply touring famous periods or countries.

Classroom example: A Year 5 class compares two movements of people connected to its region. Learners use maps to trace routes, historical sources to establish causes and population data to describe change. They then write a museum label explaining how one local place was altered by migration.

Planning caution: Avoid pairing events only because both involve travel or happened in the past. Historical comparisons require chronology, context and careful source work. Do not ask learners to make moral judgements before they know enough about the people, conditions and evidence involved.

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How we express ourselves

Plain-language meaning: This theme concerns the ways people create, communicate and interpret ideas, feelings, values, culture and imagination. Language, literature, visual art, music, drama, design and digital media can all contribute when their disciplinary methods matter to the inquiry.

Classroom example: A Year 6 class studies how public messages influence an audience. Learners analyse the composition, language and purpose of several local campaign posters. They test alternative headlines, justify visual choices and create a short campaign for a real school issue, with an artist's statement explaining the intended effect.

Planning caution: Creative choice is not a substitute for teaching craft. Model how experts use colour, structure, vocabulary, rhythm or viewpoint. Assess the knowledge and techniques learners were taught, not confidence, expensive materials or the polish that learners may have gained through help at home.

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How the world works

Plain-language meaning: This theme invites inquiry into the natural world, scientific principles, technological systems and the effects of innovation. Learners should ask testable questions, use accurate models and distinguish observation from explanation. Digital systems may fit, but only where the unit retains a clear scientific or technological focus.

Classroom example: A Year 5 class investigates why surface water collects around the school. Learners measure rainfall, test the permeability of materials and map drainage. They compare their findings with several suggested explanations, then recommend one change while stating what their evidence cannot yet prove.

Planning caution: Do not let a broad sustainability story replace science. Teach the relevant vocabulary, variables, measuring techniques and safety procedures directly. A model, simulation or generated answer is not evidence about the local site until learners check it against observations and reliable data.

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How we organise ourselves

Plain-language meaning: This theme explores how communities create systems, institutions and processes. Units may examine governance, economies, work, public services, communication or decision making. Learners consider who designed a system, whom it serves, how its parts interact and how evidence could inform improvement.

Classroom example: A Year 4 class examines the school lunch system. Learners map the journey from ordering to serving, calculate food waste and interview staff about constraints. Groups propose one realistic change, using a process diagram and costed evidence rather than relying on a popularity vote.

Planning caution: A classroom shop or mock election can become role play without learning. Identify the economic, civic or mathematical knowledge in advance. Make trade-offs visible and avoid presenting complex public systems as if one simple rule or individual choice could solve every problem.

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Sharing the planet

Plain-language meaning: This theme addresses relationships among people, other living things and shared environments. It can bring together biodiversity, resources, peace, conflict, rights, responsibilities and sustainability. Good units examine competing needs and the consequences of choices at a scale learners can understand.

Classroom example: A Year 6 class conducts a school water audit. Learners interpret meter readings, locate high-use routines, study how local water is supplied and hear two perspectives on conservation. They present leaders with a proposal that includes expected savings, likely objections and a method for checking whether the change works.

Planning caution: Avoid asking learners to solve a global crisis through posters or personal pledges alone. Use local evidence, represent more than one perspective and distinguish individual action from decisions made by organisations or governments. Hopeful action should follow understanding, not replace it.

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How to Plan a Balanced Programme of Inquiry

A balanced Programme of Inquiry gives learners repeated access to all six themes while protecting progression in each subject. Leaders map the programme across year groups, check the balance of concepts and contexts, and keep a separate view of subject coverage. Teams then design units where connections are necessary, not decorative.

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Start with the governing requirements

Use the current official How the PYP works page and PYP curriculum framework, then consult the controlled materials available to authorised schools. Under the official Programme standards and practices, schools plan six units of inquiry across the year, with one opportunity under each theme. The stated exception allows learners aged 3 to 5 to engage with at least four units. Schools must verify how the current standards apply to their setting rather than treating this summary as compliance guidance.

Next, review the whole map. A balanced programme does not mean six units of equal length or an identical subject mix. It means that important knowledge is sequenced, contexts are not needlessly repeated, and learners meet a deliberate range of perspectives, places and scales over time.

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Keep two curriculum maps side by side

The Programme of Inquiry shows transdisciplinary coherence. A subject progression map shows what learners will know and be able to do in English, maths, science, humanities, the arts and other disciplines. Leaders need both. The theme grid alone cannot show whether fractions, historical source analysis or scientific measurement develop in a logical sequence.

Planning check	Programme of Inquiry view	Subject progression view
What connects this learning?	Theme, central idea and lines of inquiry	Relevant disciplinary concepts and methods
What is taught in sequence?	Concepts and contexts revisited across years	Knowledge, vocabulary and skills from simple to complex
What counts as evidence?	Understanding of the central idea and purposeful action	Recall, accuracy and use of subject methods
What sits outside the unit?	Connections that are not authentic	Stand-alone lessons and practice that protect progression

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Build each unit from a worthwhile relationship

Before choosing activities, write a central idea that names a relationship worth investigating. The PYP key concepts can help teams test whether the idea supports questions about form, function, causation, change, connection, perspective or responsibility. Do not squeeze several abstract nouns together and assume a conceptual unit will follow.

A weak starting point is "Rivers". A more useful relationship is "Access to water influences where communities develop". This gives geography and science distinct work to do. Learners need map knowledge, physical processes and evidence about settlements before they can explain the relationship.

Use three checks before approving a connection:

• Does the subject contribute knowledge or a method that learners need to answer the inquiry?
• Would removing that subject make the final explanation less accurate or less useful?
• Can the team name what will be explicitly taught, practised and assessed within that subject?

If the answer is no, teach the objective separately. Authentic connections belong in the unit. Knowledge and skills without an authentic connection can and should be taught outside it.

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Plan knowledge, inquiry and assessment together

Use the school's agreed process for unit of inquiry planning. Identify what learners already know, the new vocabulary and content they need, the questions worth investigating and the evidence that would demonstrate understanding. Decide where direct explanations, worked examples and guided practice are needed before independent investigation.

Map a small number of approaches to learning that the unit genuinely exercises. Name observable behaviours, such as selecting relevant sources or revising a plan after feedback. Avoid adding every ATL skill to the planner. The IB learner profile should likewise appear through choices, discussion and evidence, not as labels attached after the unit is written.

Design PYP assessment before the activity sequence. A useful assessment plan checks three related outcomes:

• Knowledge: Can learners recall and explain the essential content and vocabulary?
• Disciplinary practice: Can they use the relevant method accurately, such as measuring, mapping or analysing a source?
• Conceptual understanding: Can they use evidence to explain the central relationship in a new but reachable example?

Research on this way of teaching shows that teams need time to plan, agree what terms mean and make each subject's role clear. A theme name on its own does not join the work up (Drake et al., 2015).

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A leader's map review in practice

Print the map at a size that the whole team can read. Give each theme one mark, each key idea one mark and each main place or time span one mark. Ask staff to look for gaps, clusters and repeats.

Do this first without scores. The aim is to see the shape of the planned work.

Next, take one year group at a time. For each unit, ask: What will the class know by the end? What will they learn to do?

Which part of the final task proves each aim? If the team can name only a broad theme or a fun task, the unit needs more work.

Then take one subject at a time. Track where key facts and skills are first taught, used with help and used with less help. Look for long gaps.

Check that later work asks more of the class. A new theme does not prove that the subject has moved on.

Use a simple code for the result:

• Keep: The link is clear, the subject work has depth and the task yields sound proof.
• Tune: The main plan works, but one aim, task or check needs to be made clear.
• Move: The content has value but fits a new unit or a stand-alone slot far better.
• Stop: The task adds work but does not help the class reach an agreed aim.

End the review with named actions, owners and dates. Do not ask each team to fix the whole map at once. Pick the few changes that guard the most vital subject work or remove the most clear repeat. Review those changes after the unit has been taught.

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What Changed in the 2024 Theme Descriptors

Revised PYP transdisciplinary theme descriptors were released in December 2024, with a transition period ending in September 2027, according to Sims (2025). The change requires schools to review the alignment of existing units. It does not authorise public guides to reproduce controlled wording or to present an informal summary as the official text.

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Use the transition as a review, not a search-and-replace exercise

The practical task is to compare each central idea and its lines of inquiry with the current descriptor available through authorised IB channels. Sims' guide to transdisciplinary learning records the December 2024 release and September 2027 transition deadline (Sims, 2025). Authorised schools should verify the controlled wording, implementation expectations and any later updates in the IB Programme Resource Centre.

This article deliberately keeps the exact six official theme names but does not reproduce or closely paraphrase the revised descriptor text as if it were public official wording. The IB's public curriculum pages explain the framework at a high level. The Programme Resource Centre remains the appropriate source for controlled documentation.

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A coordinator's transition checklist

• Record the descriptor version currently used in every planner and staff template.
• Give teams access to the controlled current wording through the school's authorised route.
• Review central ideas for genuine alignment, not merely repeated vocabulary.
• Check whether the planned subject knowledge still supports the revised direction of the unit.
• Identify units that need a small adjustment, a substantial redesign or no change.
• Agree when revised units will be taught, reviewed and quality assured before September 2027.
• Keep evidence of the decision, including the version checked and the people involved.

Do not change every unit at once. Begin with obvious mismatches and repeated contexts, then protect planning time for the units that require redesign. A staged review gives teachers a chance to test whether the revised central idea produces better questions and clearer evidence before it becomes part of the long-term map.

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A Teacher's Quick-Start Planning Routine

A practical planning routine can take a team from curriculum requirements to a coherent first draft in one focussed meeting. The aim is not to complete every planner box. It is to agree the learning relationship, necessary subject knowledge, inquiry sequence and evidence before attractive activities take over.

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Step 1: Mark the non-negotiable subject content

Bring the subject progression documents, prior assessment evidence and current theme descriptor. Highlight the knowledge, vocabulary and methods learners need next. Note misconceptions likely to block the inquiry. This creates the boundary within which learner agency can operate.

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Step 2: Write and test the central idea

Draft one sentence that links concepts in a meaningful relationship. Test it with three questions: Is it worth understanding? Does it need the selected disciplines?

Can learners gather evidence for or against it? Remove decorative wording and avoid claims so broad that any activity could appear to fit.

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Step 3: Draft a purposeful inquiry sequence

Use an inquiry cycle as a flexible planning tool rather than a fixed set of classroom stages. A sound sequence often moves through the following pattern:

1. Establish: Check prior knowledge and introduce essential vocabulary or a puzzling case.
2. Teach: Explain and model the subject content learners cannot reasonably discover unaided.
3. Investigate: Gather, compare or test evidence through structured questions.
4. Connect: Use discussion and writing to relate findings to the central idea.
5. Apply: Ask learners to explain, design or decide in a new but accessible context.
6. Review: Revisit the central idea and identify what the evidence supports, complicates or leaves uncertain.

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Step 4: Specify what the teacher and learners will do

Replace vague planner verbs such as explore, understand and engage with observable actions. Write "the teacher models how to distinguish a claim from evidence" and "learners annotate two sources and justify which better supports the claim". This makes scaffolding, assessment and adaptation much easier to discuss.

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Step 5: Build one worked assessment example

For the water and settlement central idea, learners receive a map, rainfall data and short accounts from two communities. They write a recommendation about where a new facility should be located. The response must use geographical vocabulary, interpret the data and explain how water access influences development.

Show the class a brief worked example using a different place. Think aloud about selecting evidence, rejecting an irrelevant fact and qualifying a conclusion. Then reduce support gradually. This preserves inquiry while making the intellectual process visible.

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A 20-minute team planning protocol

• Minutes 0 to 4: Read the governing descriptor and subject requirements silently.
• Minutes 5 to 8: Agree the central relationship and identify one likely misconception.
• Minutes 9 to 12: Allocate direct teaching and authentic disciplinary contributions.
• Minutes 13 to 16: Draft the assessment evidence for knowledge, method and conceptual understanding.
• Minutes 17 to 20: Remove forced links, name stand-alone teaching and assign the next planning actions.

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A worked five-lesson start

This short run shows how a water unit can begin. It is not a full unit plan. Its job is to build the facts, terms and habits that the class will need when the task gets more open.

Lesson 1: Start with a real case. Show a map of the school site after rain. Ask the class to mark where water tends to pool.

Gather first thoughts, but do not vote on the best cause. Teach the words drain, slope, soil, flow and surface. End with a quick match of each word to a photo.

Lesson 2: Teach how to make a fair test. Model how the same cup of water can be poured through sand, clay and gravel. Keep the cup, time and amount the same.

Ask pairs to spot what changes and what stays fixed. Each group then runs one test and logs the result in a set grid.

Lesson 3: Read the site. Walk a safe route near the school. Groups use a map, a ruler and a check sheet.

They note the ground type, slope, drains and signs of past flow. Back in class, they add their facts to one shared map. Ask which notes are facts and which are first guesses.

Lesson 4: Use maths to test a claim. Give the class a small set of rain and depth data. Model one line graph and one mean.

Learners make the next graph, then test this claim: "The place with most rain has the most pooled water." Some data may fit. Some may not. Ask them to state what else could cause the change.

Lesson 5: Write a first view. Give a short frame: claim, two facts, cause, doubt and next test. Model it with a site that the class did not study.

Learners then write about the school. They swap work and mark the facts used. The teacher reads the work to choose what to teach next.

At the end of the week, the class has not solved the whole issue. That is fine. They have key words, a test method, site facts, a graph and a first claim. The next phase can now ask for more choice because the class has a base from which to think.

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Common Questions About PYP Themes

Teachers most often ask how many units are required, whether themes or central ideas can repeat, and how stand-alone subjects fit. The short answer is that schools need a coherent programme, not forced integration. Current official standards and controlled guidance should settle compliance questions; curriculum judgement then shapes the local design.

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How many PYP units of inquiry are required each year?

The official Programme standards and practices set the expectation of six units across the year, providing an opportunity to engage with all six themes. The stated exception allows learners aged 3 to 5 to engage with at least four units. Treat this as a planning summary only. Authorised schools should check the current controlled standard, its definitions and any applicable implementation guidance.

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Must every subject appear in every unit?

No. Include a subject when its knowledge or method is genuinely needed to investigate the central idea. If spelling, number fluency, instrumental technique or another objective has no authentic connection, teach it separately. Forced integration weakens subject clarity and makes assessment less reliable.

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Can a transdisciplinary theme repeat every year?

Yes. The six themes recur across the Programme of Inquiry. What should develop is the sophistication of the central ideas, contexts, subject knowledge and learner response. Leaders should check for accidental repetition, such as several year groups studying almost identical versions of recycling, celebrations or migration.

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Can central ideas repeat across year groups?

Schools should design a coherent map in which each unit has a distinct purpose. The same broad concepts will recur, but repeating a central idea usually signals duplication. If a proposed idea resembles an earlier unit, compare the relationship, disciplinary demand, context and assessment. Revise it unless the progression is explicit and worthwhile.

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How long should a unit last?

There is no single classroom length that guarantees quality. Set enough time to teach the required content, conduct a meaningful investigation and assess the central idea without stretching a thin question across weeks. A shorter, focussed unit is better than a long collection of loosely connected activities.

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How should teachers assess transfer?

First check whether learners know the facts and methods taught. Then give them a carefully chosen new example that shares the relevant underlying relationship without changing everything at once. Ask them to explain which knowledge applies and why. One successful performance is promising evidence, not proof that understanding will transfer everywhere.

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Does inquiry mean learners choose everything?

No. Learner questions and choices can strengthen ownership, but teachers remain responsible for curriculum, accuracy, safety and appropriate challenge. Novices often need clear explanations, models and guided practice before they can investigate productively. Choice works best within boundaries that protect the intended learning.

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Limitations and Practical Safeguards

Transdisciplinary planning can create coherence, but it can also hide gaps, overload novices or reward confident performance more than secure learning. The practical safeguard is disciplined design: protect subject progression, teach essential content explicitly, control the complexity of inquiry and collect evidence that distinguishes knowledge, method and conceptual understanding.

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Transfer is difficult and context dependent

Learners do not automatically carry an idea such as systems or change from biology into history. They first need enough knowledge of both contexts to recognise the relationship. Plan deliberate comparison, point out the relevant similarities and differences, then test understanding with a reachable new case.

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Open tasks can conceal missing knowledge

A polished presentation may hide weak science, copied language or a misunderstanding of the central idea. Use short checks throughout the unit: vocabulary retrieval, annotated diagrams, oral explanations, source comparisons and worked problems. These reveal what to reteach before the final performance.

Give novice learners the explanations, examples and scaffolds needed to begin. Reduce support when classroom evidence shows they can complete the intellectual step independently. This is guided inquiry, not a retreat from inquiry.

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Integration can dilute subject rigour

A theme does not turn every activity into transdisciplinary learning. Ask subject leaders to review whether the knowledge is accurate, sequenced and assessed appropriately. Keep stand-alone timetables for content that does not fit. Make subject methods visible in learner work, including calculation, source evaluation, observation, composition and revision.

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Broad themes can flatten community perspectives

Shared human questions do not have one universal answer. Check whose knowledge, language and history appear in the unit. Use local expertise carefully, avoid asking individual learners to represent an entire group and provide different ways to contribute. Teach the conventions of academic talk and writing explicitly rather than leaving learners to infer hidden rules.

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Action can become tokenistic

Action should emerge from understanding and remain proportionate to learners' influence. A letter, redesign or changed classroom routine can be worthwhile if learners identify a real audience, use evidence and review the outcome. Avoid promising that a poster or pledge will solve a systemic problem.

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A final planning safeguard

Before teaching, ask one colleague who did not design the unit to locate four things: the central relationship, the essential subject knowledge, the point of each major task and the evidence of learning. If any is hard to find, simplify the plan. Clarity for adults makes purposeful inquiry more likely for learners.

Watch for these signs in the first week. The class can name the theme but not the key facts. Groups spend more time on roles than on the task.

A choice of format hides what each learner knows. A fun task has no clear link to the main idea. The same few voices lead each talk.

Work from home shapes the final mark. Each sign calls for a small, prompt change.

Pause and teach the facts that are missing. Cut a task that adds no value. Give each learner a brief piece of work to do alone.

Model how to take a turn, cite a fact or test a claim. Show what good work looks like and why. Use a short check the next day.

Keep the change if it helps; change it again if it does not.

At the end of the unit, save more than the final display. Keep a few first and last drafts, short test results and notes on the help that was used. Meet as a team and ask what the class learnt, what still caused strain and what should change next time. This turns the map into a tool that grows through use.

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References

These sources establish the current public PYP framework, the research context for transdisciplinary practice and the reported transition timeline. Controlled programme wording should still be checked through authorised IB channels.

• Drake et al. (2015). An exploration of the policy and practice of transdisciplinarity in the International Baccalaureate Primary Years Programme. International Baccalaureate.
• International Baccalaureate. (2026). How the PYP works. International Baccalaureate.
• International Baccalaureate. (2026). PYP curriculum framework. International Baccalaureate.
• Sims (2025). Transdisciplinary learning in IB: A guide for teachers. CASIE.