---
title: "How to Write a Strong IB Internal Assessment: Topic, Timeline, Rubric"
description: "Choose a researchable IA topic, follow a Grade 11 to 12 timeline, avoid common mistakes and see how much the IA counts in each HL subject."
url: https://bosenacademics.com/blog/ib-internal-assessment-guide-3/
published: 2026-10-08T01:34:58Z
updated: 2026-11-12T17:05:00Z
section: "IB Diploma"
publisher: Bosen Academics (https://bosenacademics.com)
---

# How to Write a Strong IB Internal Assessment: Topic, Timeline, Rubric

**The short answer:** The IB Internal Assessment usually counts for 20 to 30 percent of a subject grade and is marked by your teacher, then moderated by the IB. To score well, choose a narrow, personally interesting topic with a clear method, start in the spring of Grade 11, and write against the published rubric criteria.

For IB Diploma students, the Internal Assessment is one of the biggest pieces of academic work of high school. A Math IA exploration, a Chemistry HL lab investigation, a History HL paper or an English individual oral: whichever you are doing, the IA usually makes up 20 to 30 percent of the final subject grade. Unlike the final exams at the end of the Diploma year, it is fully in your hands.

The difficulty is that many students underestimate how early to begin, and how much guidance it takes to land on a topic that can actually be researched and is sized correctly. This guide covers what you need to know to write an IA that earns strong marks in any subject.

## What Is the IB Internal Assessment, and How Much Is It Worth?

The Internal Assessment is subject-specific work that your teacher marks and the IB then moderates externally. Formats differ by subject, but the aim is the same: to let students show independent inquiry and subject skills on a topic they care about.

This is what the IA contributes to the final grade in common HL subjects:

| Subject | IA Type | IA Weighting |
|---|---|---|
| Mathematics AA HL / AI HL | Mathematical Exploration | 20% |
| Chemistry HL | Individual Investigation | 20% |
| Biology HL | Individual Investigation | 20% |
| Physics HL | Individual Investigation | 20% |
| History HL | Historical Investigation (2,200 words) | 20% |
| Economics HL | Portfolio (three commentaries) | 20% |
| English Literature HL | Individual Oral | 20% |
| Psychology HL | Research Proposal (new course, first assessed May 2027) | 20% |

These are the HL weightings. At SL the IA often counts for more, for example 25% in History and 30% in Economics, Psychology and English. An IB examiner can move your teacher’s marks up or down, because the IA is moderated externally. For that reason, learn the actual IB rubric criteria and not only what your school stresses.

## How Do You Choose a Good IA Topic?

The key decision is picking a topic that is specific, original and truly investigable within the subject’s limits. A broad or fuzzy topic is the top reason students earn low IA marks, however well they write and however hard they work.

Experienced IB educators say the best topics share three traits:

1. **The right scope.** The topic should be narrow enough to cover in depth within the word or page limit. In a Math IA, “calculus” is much too broad, while “modelling the spread of a social media trend using logistic growth functions” is well sized.
2. **Real personal interest.** IB examiners openly reward personal engagement. Students who tie their IA to a genuine interest, something seen in daily life or a question from their own surroundings, tend to write stronger work.
3. **Access to data or a clear method.** Before settling on a topic, ask what data you will gather or what experiments you will run. Students at IB schools such as Upper Canada College, Branksome Hall and Havergal College often have excellent lab equipment, yet the investigation still needs a clear design from the beginning.

One quick test for a proposed topic: can you state it as a clear, specific research question? If you cannot, it is not yet narrow enough.

## What Timeline Should You Follow?

Most IB schools start the IA process in Grade 11 and expect completion between November and February of Grade 12, depending on the school's own deadline. A workable schedule for most HL subjects looks like this:

- **March to May (Grade 11):** Start exploring possible topics. Talk through ideas with your teacher and, if you work with a tutor, look at what strong past IAs in your subject look like.
- **June to August (between Grade 11 and 12):** Settle your research question. Start data collection or experiment design. In the sciences, run a pilot experiment before school starts if you can.
- **September to October (Grade 12):** Finish a first full draft. Collect feedback from your teacher and revise in substance.
- **November to January (Grade 12):** Hand your final IA to your teacher by your school's deadline for internal assessment.

Waiting until September of Grade 12 to choose a topic puts you behind already. From our work with students at top IB schools across Canada and the US, those who begin in the spring of Grade 11 consistently produce better work and feel less stress during the demanding Grade 12 exam period.

## Which Mistakes Cost the Most Marks?

In our experience with IB students, these are the errors that most reliably lose marks:

- **Ignoring the rubric criteria.** Every IA has assessment criteria published by the IB. Students who never go back to them miss easy marks.
- **Picking an overused topic.** Examiners moderate thousands of IAs each year. A topic done too many times will not score well on personal engagement unless it has a truly original angle.
- **Treating it like a school essay.** The IA is not a classroom assignment. It demands independent inquiry rather than a summary of what you have learned, and even strong students slip here.
- **Weak analysis or evaluation.** In the sciences, students often describe what happened in the experiment but do not critically assess the method, discuss sources of error or compare results with accepted values.
- **Poor structure and presentation.** The IA should read as focused, well-organized academic writing, with a clear introduction, methodology, analysis and conclusion. Uneven formatting or citation style makes a poor impression on examiners.

## How Can a Tutor Help With the Internal Assessment?

A good IB tutor can offer guidance that classroom teachers often lack the time to give. A tutor who has taught IB in the classroom can help a student find a strong research question, read drafts with real knowledge of what the rubric expects, and give frank, subject-specific feedback in line with what an examiner would look for.

This matters most for the Math IA, where many students are unsure how to reach the expected level of mathematical sophistication, and for the sciences, where a rigorous method has to be designed before any data is collected. Help from an experienced IB educator at the right moment can save weeks of wasted effort and noticeably raise the final mark.

You can see the [full range of IB Diploma subjects we support](https://bosenacademics.com/tutoring/) at both HL and SL levels.

The IA is among the most consequential pieces of work in the Diploma Programme, and the students who do best start early, pick a well-scoped topic and understand the criteria from day one. Done well, it can also be one of the most rewarding academic experiences in the IB.

If you are an IB student, or a parent looking for help with Internal Assessments, Bosen Academics works with Diploma students across all six subject areas. Our tutors are experienced IB educators who know what examiners look for. [Book a free consultation](https://bosenacademics.com/consultation/) to learn how we can support your child’s IA.

## Frequently asked questions

### How long should an IB Internal Assessment be?

It varies by subject. Math explorations typically run 12 to 20 pages. Biology, Chemistry and Physics investigation reports are capped at 3,000 words. History IAs are capped at 2,200 words and English individual orals run 15 minutes, including teacher questions. Check the latest subject guide for your exam year.

### Can I get help from a tutor on my IA?

Yes, within limits. A tutor can help you choose a topic, refine the research question, comment on drafts and explain each rubric criterion. A tutor cannot write the IA or collect your data, because the work must be authentically yours.

### What makes a good IB Math IA topic?

A good topic has real mathematical content at or above course level, a personal motivation or real-world link, and a focused research question explored with techniques the student truly understands. Examples include modelling phenomena with differential equations, sequences in music or nature, or probability in a familiar sport or game.

### When are IAs sent to the IB for moderation?

Teachers usually send IA marks and samples in the spring of the final Diploma year, for the May session. If the examiner's marks differ significantly from the teacher's, the whole cohort's scores are adjusted, so IA quality matters even when your teacher gives you a high mark.

### How is the IA different from the Extended Essay?

The IA is a subject-specific piece completed in each of your six Diploma subjects and contributes to that subject grade. The Extended Essay is a separate 4,000-word research paper in one subject of your choice and counts toward Core points. Both are required and assessed independently.

## Tutoring from Bosen Academics

One-on-one tutoring from certified teachers and subject experts with master's and PhD degrees, in person in North York, Toronto, or online. Book a free consultation: https://bosenacademics.com/consultation/