How to Write an IB Internal Assessment (IA): A Subject-by-Subject Guide for 2026

The Internal Assessment (IA) is the most-controlled, highest-leverage piece of work in the IB Diploma. It is worth 20% of your final grade in most subjects (25% in some). It is not sat under exam conditions. It is graded against a published rubric you can read line by line. And — quietly — it is the single component where coaching most reliably lifts a student a full grade band.

Most students treat the IA like a school project. The students who score in the top band treat it like the engineered, mark-scheme-aligned piece of work it actually is. This guide explains how.

Quick answer: what is an IB Internal Assessment?

The IB Internal Assessment is a piece of independent research or analytical work that every IB Diploma student completes in each of their six subjects. It is graded internally by your teacher against the IB's published rubric and externally moderated by the IB. It contributes between 20% and 30% of the final subject grade, depending on the course.

The IA looks different in every subject — a mathematical exploration in Math, an experimental write-up in Sciences, a portfolio in English, a commentary in Economics — but the graded criteria are similar in structure across subjects, and the strategies that win marks are nearly identical.

How the IA is weighted across IB subjects

(These weightings are stable across the 2025–2027 cycle; always check your school's confirmed assessment outline.)

The seven habits of every top-band IA

Across every subject, the IB rubric rewards seven specific habits. These are the most reliable indicators of a 7-grade IA in any subject.

1. A narrow, specific research question

The single biggest predictor of IA grade is the width of the research question. A narrow, focused question is the starting condition for a top band; a broad, vague one caps the work at the middle band, regardless of how well it's written.

• ❌ Too broad: How does temperature affect enzyme activity?

• ✅ Narrow: To what extent does temperature (15°C–55°C) affect the rate of catalase activity in fresh potato samples, measured by O₂ production over 60 seconds?

A good IA research question is 15–25 words, includes a specific independent variable, a specific dependent variable, and a clear measurement method.

2. Methodology that matches the subject and level

The methodology must be one that examiners recognise as rigorous in the subject and appropriate to the level (HL or SL). A Math AA HL IA using only descriptive statistics undermarks Use of Mathematics. A History HL IA without engagement with primary sources undermarks the equivalent criterion. Match the method to what the subject's rubric expects.

3. Genuine personal engagement

Every IB IA rubric rewards personal engagement — your own data, your own choice of focus, your own twist. Examiners read dozens of generic IAs on Newton's law of cooling, the spread of COVID-19, and the impact of demonetisation. The ones that score full marks in Personal Engagement have a clear you in them — your own data collection, your own irreverent question, your own admitted dead-ends.

4. Critical reflection threaded throughout

The strongest IAs reflect during the work, not at the end. Not "I learned a lot" but "I initially measured at 5-second intervals and noticed the readings were too granular to fit a clean curve, so I revised to 15-second intervals — this lost resolution at the early stage but improved the overall fit substantially."

5. Mark-scheme-aligned language

Every IB rubric is written in specific terminology — commensurate with the level of the course, coherent, consistent, thorough. Top-band IAs use the rubric's own language explicitly when describing what they've done, making the moderator's job easy.

6. A logical, scannable structure

Examiners moderate hundreds of IAs. Structure that lets them find every section in 30 seconds is a presentation criterion gift. Use clear headings, numbered figures, captioned tables, and a consistent style.

7. A drafting cycle of at least three rounds

Top-band IAs are rarely first-draft work. They are drafted, critiqued, revised, critiqued again, and polished. Most students draft once and submit. Students aiming for the top band leave six to eight weeks for revision after the first complete draft.

IA structure by subject

Math IA (Math AA HL/SL and Math AI HL/SL)

Length: 12–20 pages Worth: 20% of final grade Format: Mathematical Exploration

Required structure: 1. Introduction — research question, personal motivation, mathematical context 2. Mathematical exploration — the maths itself, fully worked 3. Analysis and discussion — interpretation of results, comparison to alternatives 4. Conclusion — direct answer to the research question 5. Reflection — limitations, what could be improved, what would come next 6. Bibliography — every source cited

Top-band signals: mathematics at the level of the course, original twist on the topic, clear mathematical communication, errors caught and corrected with reasoning shown.

For a complete topic list and selection framework, see Educifly's guide to IB Math IA topics.

Science IA (Physics, Chemistry, Biology — HL/SL)

Length: 6–12 pages (the IB recommends not exceeding 12) Worth: 20% of final grade Format: Scientific Investigation

Required structure: 1. Research question — narrow, specific, with controlled variables identified 2. Background and rationale — theoretical context and hypothesis 3. Methodology — variables, controls, measurement methods, safety/ethics 4. Results — raw data tables, processed data, graphs with error bars 5. Analysis — interpretation of results, comparison to theory, error analysis 6. Conclusion — direct answer to the research question 7. Evaluation — limitations of the method, sources of error, suggested improvements 8. References — every source cited

Top-band signals: primary data collected by the student, controlled variables explicitly identified and held constant, uncertainty quantified (percentage error or standard deviation), error analysis that goes beyond "human error" and identifies specific sources of uncertainty.

Economics IA

Length: Three commentaries of 800 words each (2,400 words total) Worth: 20% of final grade (HL and SL) Format: A portfolio of 3 commentaries, each based on a different news article from a different unit, applying distinct economic theory

Required structure for each commentary: 1. Identification of the relevant economic concept 2. Diagram with full labelling and clear reference in the text 3. Explanation of the concept using the article 4. Evaluation — short-run vs long-run, stakeholders, alternatives

Top-band signals: recent articles (within the last year), three articles from three distinct units, diagrams referenced explicitly in the prose, evaluation that weighs stakeholders rather than listing them.

History IA

Length: 2,200 words Worth: 20% (HL) / 25% (SL) Format: Historical Investigation, in three sections

Required structure: 1. Section 1: Identification and Evaluation of Sources (~500 words) — identify the question, list 2–3 main sources, evaluate two of them for origin, purpose, value, limitations 2. Section 2: Investigation (~1,300 words) — the historical investigation itself, argued from the sources 3. Section 3: Reflection (~400 words) — what the investigation taught you about the methods historians use

Top-band signals: narrow question, balanced primary and secondary sources, OPVL analysis (Origin, Purpose, Value, Limitations) done thoroughly, reflection on historiography (not just on personal feelings).

English IA (Individual Oral, IO)

Length: 15 minutes (10-minute presentation + 5-minute discussion) Worth: 30% (SL) / 20% (HL) Format: A spoken commentary connecting one literary work and one non-literary text to a global issue

Required structure: 1. Introduction to the global issue and the two texts 2. Analysis of the literary work through the lens of the global issue 3. Analysis of the non-literary text through the same lens 4. Connection between the two 5. Discussion with the teacher (last 5 minutes)

Top-band signals: a global issue you genuinely care about, close analytical attention to specific textual features (not summary), confident voice, willingness to argue your own reading rather than recite secondary criticism.

Psychology IA

Length: ~2,200 words Worth: 20% (HL) / 25% (SL) Format: A replication of a published experimental study with your own sample

Required structure: 1. Introduction (theory, hypothesis) 2. Method (participants, materials, procedure) 3. Results (descriptive and inferential statistics) 4. Discussion (interpretation, comparison to original, limitations)

Top-band signals: ethically clean methodology, statistical test correctly chosen and applied, comparison to the original study's findings handled with nuance.

Business Management IA

Length: 2,000 words (SL) / 1,800 words (HL) Worth: 25% (HL) / 30% (SL) Format: Research Project on a real organisation, addressing a real issue

Top-band signals: primary data from the organisation itself (interviews, internal data with permission), application of 2–3 relevant frameworks (not all of them), evaluation rather than description, recommendations grounded in the analysis.

A 12-week IA writing timeline

The students who score top-band IAs work to a schedule. Here is a realistic 12-week plan from topic selection to submission.

Week 1 — Topic generation. Brainstorm 5–10 candidate topics. Test each against the IA criteria. Pick a top 3.

Week 2 — Topic lock and supervisor sign-off. Write a one-page proposal for your top choice. Send it to your IA supervisor for feedback. Lock the topic.

Weeks 3–4 — Background research and methodology design. Read the rubric line by line. Build the methodology. For sciences, run a pilot. For history, identify sources. For economics, pick articles.

Weeks 5–6 — Data collection or primary research. Run the experiment, conduct the interview, gather the data, do the close reading.

Weeks 7–8 — First draft. Get a complete draft on paper. Don't polish — just write. Aim for full word count.

Week 9 — First supervisor review. Submit the first draft to your IA supervisor for feedback. (Many schools cap supervisor feedback at this point — check your school's rules.)

Weeks 10–11 — Revision and second draft. Apply the supervisor's feedback. Re-align with the rubric criterion by criterion. Tighten the language.

Week 12 — Final polish. Proofread. Check citations. Check word count. Submit.

This is the timeline our IB tutors use with Educifly students. It's tight, but it allows two complete drafts, structured feedback, and meaningful revision — which is what separates a 6 from a 7 on the IA.

Five mistakes that cost IA marks

Mistake 1: Choosing a topic that's been done a thousand times before

A modelling IA on Newton's law of cooling, a chemistry IA on vitamin C in oranges, a history IA on "the causes of WW1" — these score in the middle band almost regardless of execution because Personal Engagement caps low when the topic is generic. Add a twist. Use your own data. Pick a less common angle.

Mistake 2: Methodology that's too thin

"I asked 20 friends" is not a methodology. Statistical IAs need sample sizes that allow meaningful inference (usually n ≥ 30 for normal-approximation methods). Experimental IAs need controlled variables and repeated trials. History IAs need a balance of primary and secondary sources. Skimping on methodology caps the score.

Mistake 3: Treating the IA as a school project, not a piece of work for an external moderator

Your school marks the IA first. The IB moderates a sample. Moderators reduce school grades that are inflated — and most students' school grades on the IA are inflated relative to the moderated grade. Write to the IB moderator, not to your teacher.

Mistake 4: Leaving the reflection until the last day

Reflection sections in most IA rubrics are worth 15–25% of the marks. Most students treat them as 30-minute jobs at the end of the timeline. Write reflection notes as you work — what changed, what surprised you, what you'd do differently. Then synthesise them in the final section.

Mistake 5: Word count violations

Most IAs have a word-count limit. Going over by 10% is common; going over by 30% means moderators stop reading at the limit. Words don't count toward marks past the limit — but they also don't cost marks before it. Cut everything that doesn't serve the research question.

How Educifly coaches the IA

Educifly's IB specialists include former IB examiners and 15-year-veteran international-school teachers. Our IA coaching is structured around four checkpoints:

1. Topic & RQ lock — narrowing your topic and research question to one a moderator will recognise as rigorous

2. Methodology design — getting the experiment, sources, or modelling right before you collect data

3. First-draft review — structured feedback against every rubric criterion

4. Pre-submission audit — final mark-scheme alignment, citation check, presentation polish

Most students see at least a full grade-band lift on the IA after structured coaching — which can be the difference between a 6 and a 7 in the final subject grade. Book a free 30-minute trial with an Educifly specialist in your IA subject.

FAQ — IB Internal Assessment

How many words is the IB IA?

It varies by subject: Math IA is 12–20 pages (no strict word count); Science IA is 6–12 pages; History IA is 2,200 words; Economics IA is 3 commentaries of 800 words each; Business Management IA is 1,800–2,000 words; English IO is a 15-minute oral.

Is the IA harder than the IB exams?

Different. The exam tests recall, fluency, and exam-strategy under time pressure. The IA tests independent research, methodology, and writing without time pressure. Most students score higher on the IA than on the exams when they put in the coaching.

How much does the IA count toward my final IB grade?

20% in most subjects, 25–30% in some (notably Business Management and SL Psychology, History). That makes the IA equivalent to one entire exam paper in most subjects.

Can I get feedback on multiple IA drafts from my teacher?

Most schools allow detailed feedback on one full draft only, in line with IB regulations. Some allow informal early feedback. Always check your school's specific policy.

Can I use AI tools like ChatGPT for my IA?

You can use AI for clarifying concepts, brainstorming, and language polishing. Submitting AI-generated content as your own work is academic misconduct under the IB's policy and will invalidate your IA. Personal Engagement and Reflection criteria are also specifically designed to be hard to fake.

When should I start my IA?

For May-session candidates, most IAs are due around January–March of IBDP2. Starting in September of IBDP2 is realistic. Starting in May of IBDP2 is too late.

How is the IA moderated?

Your school marks every student's IA. The IB then selects a sample of IAs from your cohort and re-marks them externally. If the school's marks are consistently higher than the IB's, the whole school's IA grades are scaled down. This is why writing to the IB rubric — not just to your teacher — is critical.

Need structured IA coaching that lifts you from a 5 to a 7? Book a free trial class with an Educifly IB specialist — 30 minutes, no card, no commitment.