Internal assessments in the IB: what parents need to know

What an IA actually is

An internal assessment is a piece of school marked coursework, set by the IB but marked first by the student's subject teacher, then moderated externally by the IB. Every Diploma subject has at least one IA component, and most have one principal IA piece. The format varies by subject: an essay in history, a written portfolio in English, a series of practical write ups in the sciences, a mathematical exploration in mathematics, an oral commentary in language acquisition, a folio in the arts. Each carries a defined weighting in the final Diploma grade for that subject.

The IB sets the criteria, provides exemplar work, and publishes the marking rubric. The teacher applies the rubric to the student's work in the spring of Year 13 and submits a sample of marked work to the IB for moderation. The moderator checks the school's marking against the IB standard. If the school has marked harshly the moderator adjusts the marks up across the cohort; if the school has marked generously the moderator adjusts down. The adjustment is applied uniformly so individual students cannot move within the cohort, only the cohort as a whole moves up or down against the IB standard.

The weighting of the IA in the final subject grade ranges from 20 to 30 per cent in most subjects, with some exceptions. In subjects like the visual arts and theatre, the IA component carries closer to 40 to 60 per cent of the final grade. In mathematics and the natural sciences the IA carries 20 to 30 per cent. In language and literature the IA carries 30 per cent for HL and 20 per cent for SL. The exact figures shift with the IB's curriculum refresh cycle; the IB's subject guides hold the current numbers.

Why the IA matters

For most Diploma subjects, the IA is the most tractable component. The external examinations are sat under exam conditions in May or November and are unforgiving; a difficult question, a bad day, an unfamiliar topic, and the mark falls. The IA is produced over weeks or months in the student's own time, in the student's own subject teacher's classroom, with feedback and drafts. A student who manages the IA well captures a substantial proportion of the final grade with no exam day variance. A student who manages it badly has a hole in the grade that the external paper has to fill.

For students at the borderline between two grade bands, the IA is often the difference. A student sitting at a borderline 6 to 7 on Higher Level history can pull the final grade to a 7 with a strong IA, or fall to a 6 with a weak one. For Higher Level subjects, the IA contribution at 20 to 25 per cent of the grade is large enough to swing the final grade in either direction. The IB cohort grade distributions across the past five years show a clear correlation between IA marks and final grade outcomes; the schools that manage the IA well outperform the schools that do not.

For university applications, the IA also matters because predicted grades draw on the IA marks. The student's IA performance feeds the teacher's predicted grade for the subject, and the predicted grade feeds the university application. A strong IA in October of Year 13 supports a stronger predicted grade for the January application window. A weak IA pulls the predicted grade down. Our predicted grades explainer covers the mechanic in detail.

The realistic timeline

Most Diploma subjects start the IA in the second half of Year 12 and complete it by early Year 13. The pattern by subject group, broadly: history starts the topic in March of Year 12, completes the draft over the summer, submits by January of Year 13. Mathematics starts the exploration in April or May of Year 12, drafts over the summer, submits by November. The sciences start the practical assessment programme in Year 12 and run continuous experiments through to the autumn of Year 13. English and the language A courses run the written tasks across both years. The visual arts and theatre carry the IA across both years as the principal Diploma work.

Strong schools structure the IA timeline with checkpoints and draft deadlines. A research question approved by the teacher, a first draft by a specific date, a second draft incorporating feedback, a final submission. The strongest schools force the IA to be effectively complete before the Year 13 mocks in January, which clears the spring for revision. Weak schools let the IA drift into March of Year 13, where it competes for time with the final external examination revision and degrades both.

For parents the practical implication is the same as for the Extended Essay: ask the school in October when each subject's IA is due, what the draft schedule is, and what the contingency is for students who fall behind. A school that cannot answer these questions concretely is a school where the IA is at risk.

How the IA looks across subjects

History HL and SL: a 2,200 word historical investigation on a topic of the student's choosing. The student picks a focused research question, identifies and evaluates sources, presents the investigation and writes a reflection on the methodology. The criteria reward source analysis and methodological rigour as much as historical content. Strong IAs choose narrow, well evidenced questions; weak ones range too broadly.

Mathematics Analysis and Approaches, and Mathematics Applications and Interpretation: a 12 to 20 page mathematical exploration. The student picks a real world or mathematical topic, develops the mathematics, applies it to a question, and reflects on the modelling decisions. Strong explorations show genuine mathematical reasoning; weak ones lift textbook examples with cosmetic changes.

The natural sciences (biology, chemistry, physics): a scientific investigation built on a research question of the student's choosing, with experimental design, data collection, analysis and evaluation. The IB shifted to a single Scientific Investigation IA from 2025, replacing the old Individual Investigation. The investigation can be experimental, simulation based, or based on secondary data, depending on the subject and the student's circumstances.

English Language and Literature, and English Literature: a portfolio of written tasks across the two years, with one task selected for assessment. The student's analysis of literary or non literary texts is the focus; the IB rewards close reading and structured argument over breadth of texts covered. Modern languages: an oral examination based on a stimulus, recorded and submitted to the IB. The visual arts: a comparative study, a process portfolio and an exhibition. The IA in the arts is the principal Diploma work in the subject and carries the largest weighting.

How parents help without crossing the line

The academic integrity line is the same as for the Extended Essay. Parents must not be giving substantive feedback on the content or editing the prose. The IA must be the student's own work. Teachers can give one round of feedback on a draft, the IB allows that explicitly, but cannot write substantive comments on subsequent drafts. Parents cannot give the kind of detailed content feedback that would substitute for the teacher's role. The IB does take academic integrity in the IA seriously and confirmed breaches can result in the loss of the subject grade or the Diploma.

What parents can do. First, project management. Ask in May of Year 12 whether each IA topic has been approved by the teacher. Ask in July whether the summer drafting is happening. Ask in October whether the first draft has been submitted for feedback. The parent's role is the timeline custodian, not the academic supervisor.

Second, environment. The IA work is best done in focused blocks of two to three hours rather than scattered fifteen minute slots. A quiet desk, the relevant reading material in one place, the data or the texts accessible, the citation manager set up from the start. The parent's role is to make the focused blocks possible, not to fill them. Third, wellbeing. The Year 13 autumn is the peak workload of the Diploma, with the IA and the Extended Essay competing for time with the start of the external examination revision. A child who is working consistently is doing the right thing; a child who is panicking is signalling that the school's timeline structure is not holding. Use our TOK explainer and Extended Essay guide for the core component patterns, and our school finder to identify IB schools by city.

Related guides

• International Baccalaureate explained 2026
• IB Extended Essay parent's guide
• IB predicted grades explained

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