IB Internal Assessment: What It Is, Methods, Structure
What an IB internal assessment (IA) is, how much it is worth, how teachers mark it and the IB moderates it, and how IA structure differs by subject group.
15 minRead guide
Internal Assessment (IA) Guides
Complete resources for planning, writing, and perfecting your Internal Assessments across all IB subjects.
The Internal Assessment (IA) is the coursework part of each IB subject. In most subjects it is worth 20 to 30 percent of your final grade, and more in a few, such as Design Technology and the arts. Your teacher marks it against the subject criteria and the IB moderates a sample. Unlike exams, the IA gives you control: you choose the question, gather the data or sources, and have time to refine the work. Several subjects have new guides for 2027 candidates, including Psychology, Computer Science and Design Technology, so check which version applies to you. Our guides explain each subject's task, criteria and word limit, with topic ideas that work and the mistakes that cost marks.
Key Takeaways
- Start early - IA quality improves dramatically with time for iteration
- Understand criteria before you begin; they guide every decision
- Choose topics you genuinely find interesting; engagement shows in your writing
- Prioritise analysis and evaluation over description
- Get feedback on drafts from teachers and peers
Need personalised guidance?
Get matched with an expert tutor within 24 hours.
Guides in This Category
Biology IA Ideas: 40 Topics With Methods and Data
40 IB Biology IA topics by syllabus area, each with the method and data it needs, plus the current criteria, 3,000-word limit and research question tips.
16 minRead guide
Economics IA Structure: Criteria, Word Count, Format
IB Economics IA structure for 2026 and 2027: the 800-word rule, criteria A to F, what each commentary must include and an example commentary outline.
13 minRead guide
Physics IA Guide: Methodology, Uncertainties and Ideas
IB Physics IA guide for the current criteria: requirements, research design, controlling variables, uncertainty propagation, linearised graphs and 24 ideas.
13 minRead guide
Chemistry IA Topics: 40 Ideas With Methods and Data
40 IB Chemistry IA topics by syllabus area, each with the method and data it needs, plus example research questions, the current criteria and uncertainty tips.
16 minRead guide
Psychology IA: Research Methods and 2027 Criteria
The IB Psychology IA is now a research proposal: the four research methods, the 24-mark criteria, the 2,200-word limit and what changed from the old experiment.
13 minRead guide
Business IA Guide: BM Criteria, Word Count, Structure
IB Business Management IA explained: the 1,800-word research project, key concepts, how many supporting documents, all seven criteria and how to structure it.
12 minRead guide
Maths AA IA Ideas: 50 Topics for SL and HL
50 IB Maths AA IA ideas by syllabus area, each with why it works and the method or data it needs, plus criteria A-E, the 12-20 page length and SL vs HL.
21 minRead guide
Maths AI IA Ideas: 45 Topics With Data and Methods
45 IB Maths AI IA ideas grouped by topic, each with the data and method it needs, plus SL vs HL tools, criteria, page length and where to find reliable data.
18 minRead guide
Computer Science IA Guide: 2026 vs 2027 Criteria
IB Computer Science IA for 2026 vs 2027: the 34-mark client model, the new 30-mark computational solution, criteria, video length and project ideas.
12 minRead guide
ESS IA Guide 2026: Criteria, Ideas and Structure
IB ESS IA guide for 2026 and 2027: the 3,000-word rules, all six criteria with marks, 12 research question ideas and a report structure that scores well.
13 minRead guide
Design Technology IA: 2026 and 2027 Criteria Explained
Which IB Design Technology IA applies to you: the 2026 design project vs the new 2027 model, with criteria, hours, word limits, weightings and project ideas.
11 minRead guide
Sports Science IA Guide (SEHS): Criteria and Topics
IB SEHS IA guide for 2026 and 2027: the 3,200-word rules, all four criteria explained, 12 example research questions and the mistakes that cost marks.
15 minRead guide
How to Choose Economics IA Articles and Key Concepts
Choose IB Economics IA articles that score: the IB's article rules, a six-step test, the nine key concepts explained and article ideas for every unit.
11 minRead guide
History IA Guide: Structure, Word Count and Sources
How to write an IB History IA: the 2,200-word limit, the three sections and marks, how many sources to use, topic ideas, and what changes from May 2028.
14 minRead guide
Geography IA Guide: Structure, Word Count, Criteria
How to write the IB Geography IA (geo IA): the 2,500-word limit, the six criteria and marks, fieldwork questions, sampling, analysis and topic ideas.
11 minRead guide
Global Politics IA Guide: Structure and Criteria
The IB Global Politics IA (engagement project) for exams from May 2026: word limits, criteria and marks, the HL recommendation, structure and topic ideas.
10 minRead guide
IB English A IA Guide: Individual Oral, Marks, Timeline
The IB English A IA explained: the individual oral in Literature and Lang Lit, 30% SL and 20% HL weighting, marking and moderation, a timeline and text choice.
13 minRead guide
IB English B IA Guide: Individual Oral, Marks, Timeline
The IB English B IA explained: the individual oral at SL and HL, its 25% weighting, the 30-mark rubric, moderation, when it happens and how to prepare for it.
10 minRead guide
IB German A IA Guide: Individual Oral, Texts and Marks
The IB German A IA explained: the individual oral in German, Literature vs Language and Literature, choosing German works, self-taught rules, marks, timeline.
13 minRead guide
IB German B IA Guide: Individual Oral, Marks and Prep
The IB German B IA explained: the individual oral at SL and HL, 25% weighting, the 30-mark rubric, moderation, timing, and the themes and phrases to prepare.
11 minRead guide
Frequently Asked Questions
It depends on the subject. Biology, Chemistry and Physics allow up to 3,000 words, History and Psychology 2,200, Geography 2,500 and Business Management 1,800, while the Economics portfolio is three commentaries of up to 800 words each. The Maths exploration is measured in pages, about 12 to 20. Our subject IA guides give the exact limit for your course.
Your school sets the timeline, and it differs by subject. Many schools introduce the IA towards the end of IB1 and set internal deadlines in IB2. Starting to think early gives you time to test a research question, collect data or sources, and act on your teacher's feedback.
Yes, within the IB's academic integrity rules. A tutor can explain the criteria, help you test whether a research question is workable and practise the analysis and evaluation skills it needs. The IA itself must be your own work, and your teacher is the one who gives feedback on a draft.
Unexpected results aren't a problem. What matters is analysing why they occurred and evaluating your methodology honestly. Scientists learn from all outcomes, and the criteria reward honest evaluation.