How to check your IB IA against the official criteria (without a tutor)
Every subject Internal Assessment is marked against published criteria with fixed mark allocations (the TOK exhibition is marked holistically), which means you can check a draft against the same criteria your teacher and the moderator will use. The catch: the criteria differ completely by subject, and the smartest check starts from where the marks actually are. This guide shows what each subject is marked out of, where the heaviest criteria sit, and a self-check sequence that works for any of them.
Know what your IA is marked out of
| Subject | Marked out of | The heaviest criterion |
|---|---|---|
| Biology, Chemistry, Physics (2025 instrument) | 24 | Four equal criteria of 6: Research design, Data analysis, Conclusion, Evaluation |
| History | 25 | Criterion B: the Investigation (Section 2), 15 of 25 marks |
| Business Management | 25 | Integration of a key concept (5) and Analysis and evaluation (5) |
| Economics (per commentary) | 14 | An even spread; each commentary must use a different key concept, within 800 words |
| Mathematics (AA and AI) | 20 | Criterion E: Use of mathematics, 6 marks |
| Psychology (through Nov 2026) | 22 | Introduction, Analysis and Evaluation at 6 each |
| Computer Science (through Nov 2026) | 34 | Criterion C: Development, 12 marks |
Psychology and Computer Science change format from the May 2027 session: a research proposal out of 24 and a computational solution out of 30 respectively. If you sit exams in May 2027 or later, check against the new criteria: Psychology 2027, Computer Science 2027.
The self-check sequence
- Start with the heaviest criterion. A History IA lives or dies on the Investigation; a CS IA on Development; a Math IA is capped by the mathematics you actually use. Check that criterion first, because it moves the most marks.
- Check the limits. In several subjects the guide says marking stops at the word limit, and everywhere else it is still a rule, except in the Mathematics exploration, which has only a suggested length of about 12 to 20 pages. Check yours before polishing prose that may not be read.
- Read one criterion at a time, draft in the other hand. For each criterion ask: where exactly in my draft is the evidence for the top markband? If you cannot point to a paragraph, a moderator cannot either.
- Fix the weakest criterion before the strongest. Marks lost at the bottom are cheaper to recover than marks squeezed at the top.
Teacher feedback and where AI fits
Your teacher gives guidance during the IA process and, for most IAs, feedback on one draft (for the individual oral, on your outline and practice orals): use it for what only a subject expert can judge, such as whether your method is sound and your content accurate. What AI adds is a check against the criteria, but it is outside help, so check that your teacher and your school allow it before you use it. IBLens marks coursework drafts in 14 subjects against the criteria for your session. A range of totals and, for most drafts, your weakest criterion and the top risks are free, and the full criterion-by-criterion report is $9.99, with no subscription and two free re-checks.
See how the IA grader works → or check your draft now →
Frequently asked questions
Which IA has the heaviest single criterion?
History: the Investigation carries 15 of 25 marks, 60% of the IA. Computer Science's Development criterion (12 of 34 through November 2026, 12 of 30 from May 2027) is the other outlier.
Are the science IAs really marked identically?
Biology, Chemistry and Physics share the 2025 assessment instrument: Research design, Data analysis, Conclusion and Evaluation, 6 marks each, 24 in total, so a self-check method that works in one science transfers to the others.
Can I check my IA against the criteria myself?
Yes, the criteria are published, and this page's sequence is designed for exactly that. The hard part is objectivity about your own writing, which is where a second reader, or an AI check built on the criteria, can help, as long as your teacher and your school allow outside feedback on the work.