IB internal assessment (IA): how it works in every subject
What the IB internal assessment is, what it is worth in each subject, how your teacher marks it and the IB moderates it, and the rules on drafts and help.
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What the IA is
Most IB subjects include a piece of coursework called the internal assessment (IA). You do it during the course, not in the exam hall: an investigation, an exploration, a portfolio, an oral or a project, depending on the subject.
- Your teacher marks it against the subject's assessment criteria.
- The IB moderates it: it re-marks a sample from your school and adjusts every student's mark if your teacher marked too high or too low.
- It counts towards your subject grade, usually between 20% and 30% of it.
The IA is a part of each subject grade. It's separate from the core: theory of knowledge has its own exhibition, and the extended essay is marked by IB examiners.
The IA in each subject
| Subject | The task | Weight at SL | Weight at HL |
|---|---|---|---|
| Biology, chemistry, physics | A scientific investigation of your own research question, written up as a report of up to 3,000 words, about 10 hours of work | 20% | 20% |
| Maths AA and Maths AI | A mathematical exploration of a topic you choose, about 12 to 20 pages, 10 to 15 hours of class time | 20% | 20% |
| Environmental systems and societies | An individual investigation of a research question, a report of up to 3,000 words, about 10 hours | 25% | 20% |
| Computer science | A computational solution to a real problem you choose, about 35 hours | 30% | 20% |
| Economics | A portfolio of three commentaries on news extracts, from different units of the syllabus, about 20 hours | 30% | 20% |
| Business management | A research project on a real issue facing an organization, about 20 hours | 30% | 20% |
| Digital society | An inquiry project, about 30 hours | 30% | 20% |
| Geography | Fieldwork on a question from the syllabus, written up as one report, about 20 hours | 25% | 20% |
| History | A historical investigation of a question you choose, about 20 hours | 30% | 20% |
| Language A: language and literature | An individual oral on how a literary work and a non-literary body of work approach a global issue | 30% | 20% |
| Language B | An individual oral | 25% | 25% |
Each row comes from the subject's current guide or subject brief. Computer science's computational solution is the version first assessed in May 2027, and history's figures are for the course first assessed in May 2028. Your teacher has the guide for your own session, and every other subject's guide sets out its own task.
How IB grading works explains how the IA's marks are scaled and added to your exam marks.
How your IA is marked
- Your teacher marks it against the subject's criteria. Each criterion has levels, and the teacher picks the level that best fits the work as a whole.
- Your school sends a sample of the class's work to the IB, chosen to cover the range of marks the school gave.
- A moderator re-marks the sample. The IB compares the two sets of marks and works out an adjustment.
- Every student's mark is adjusted, not only those in the sample. If your teacher marked consistently high, everyone's mark comes down by the same amount; if the teacher was off only at the top or bottom, the adjustment differs across the range.
So the mark your teacher gives you is provisional. It can go up, down or stay the same after moderation.
What your teacher can and can't do
- Talk it through. Your teacher is expected to discuss the work with you, from choosing a topic onwards, and you can't be penalized for asking for guidance.
- Read one draft. Your teacher reads and comments on one draft, with advice on how to improve it, but doesn't edit it.
- Point to errors, not fix them. In math, for example, your teacher can show that an error exists but shouldn't correct it.
- The next version is final. The version you hand in after the draft feedback is your final version.
- No changes after submission. Once you have officially submitted the final version, you can't take it back to change it.
- Your teacher authenticates it. Every IA, not only the sample, has to be confirmed as your own work. Teachers can check by talking to you about it, comparing it with your draft and your proposal, checking the references and your usual writing, and using plagiarism software.
Working with others
In environmental systems and societies, you may work with others, in groups of three or fewer, on the research question and the method. Each student still needs their own research question, their own method and their own data, and writes their own report. [Biology, chemistry and physics follow a similar rule.] In other subjects, check with your teacher before working with anyone.
The IA and the extended essay
The same piece of work can't count as both your IA and your extended essay. In environmental systems and societies, your extended essay can't be based on the research question of your IA. If you want to write your extended essay in a subject you also have an IA in, choose a clearly different question. The IB extended essay has the EE's rules.
Deadlines
Your school sets its own internal deadlines for every IA, usually well before the exams, and it sends the work and marks to the IB. Several IAs and the extended essay often fall in the same months, so put every deadline in one calendar as soon as you have them.
Planning your IA
- Read the criteria first. Ask your teacher for the assessment criteria before you start. Every part of your IA should answer one of them.
- Choose a question you can answer in the space. A question that is too broad can't be answered properly within the word or page limit.
- Agree your question early. A short proposal your teacher has seen saves you weeks on a question that won't work.
- Keep records as you go. Raw data, sources, notes on decisions and what went wrong are all useful when you write the evaluation.
- Reference everything you didn't create, including images and data.
Our internal assessment pages go through each subject's task and criteria:
| Subject | Start here |
|---|---|
| Biology | The scientific investigation |
| Chemistry | The scientific investigation |
| Physics | The scientific investigation |
| Maths AA | The mathematical exploration |
| Maths AI | The mathematical exploration |
| Environmental systems and societies | The individual investigation |
| Computer science | The computational solution |
| Economics | The portfolio and choosing articles |
| Business management | Choosing an issue and a research question |
| Digital society | Planning the inquiry project |
| Geography | Planning fieldwork |
| History | The historical investigation |
| Psychology | The research proposal |
| Sports, exercise and health science | Planning the scientific investigation |
Retaking a subject with an IA
If you retake a subject, ask your coordinator whether your IA mark can be carried over from your first session. It depends on the subject and on whether the course has changed. Retaking a subject has the other rules.
Your work has to be your own
The IB defines academic misconduct as anything that gives you, or another student, an unfair advantage, whether you meant it or not. For the IA, that includes:
- copying words, ideas, data or images without saying where they came from;
- handing in work that someone or something else wrote for you;
- working together on parts that have to be your own, which the IB calls collusion;
- handing in the same work for two assessments.
Penalties range from losing marks to receiving no grade for the subject, and with no grade in a subject you don't get the Diploma.
- International Baccalaureate. Understanding DP assessment. Internal assessment marked by teachers and moderated by the IB.
- International Baccalaureate. IB assessment principles and practices: a guide to assessment for teachers and coordinators. How the moderation sample is chosen and how adjustments work.
- International Baccalaureate. Subject briefs: Biology, Chemistry and Physics (first assessment 2025); Mathematics: analysis and approaches (2021); Computer science (2027); Economics SL and HL (2022); Business management SL and HL (2024); Digital society (2024); Geography (2019); History (2028); Language A: language and literature (2021); Language B (2020).
- International Baccalaureate. Mathematics: applications and interpretation guide, first assessment 2021. The exploration's length and hours, one draft, errors pointed out but not corrected, and authenticity.
- International Baccalaureate. Environmental systems and societies guide, first assessment 2026. The individual investigation, weightings, one draft, authenticity checks, group work, and the IA and the extended essay.
- International Baccalaureate. Diploma Programme Assessment procedures 2026, part B: General regulations. IA carried over on a retake (article 9.3) and academic misconduct (article 16).
- International Baccalaureate. Retaking examinations.
- International Baccalaureate. Academic integrity policy (2019). Forms of misconduct and penalties.