Most Diploma students worry about the exams. A surprising share of a final grade is settled months earlier, in a piece of work that is easy to understand, easy to postpone, and marked in a way that rewards something different from the exam.
Every subject in the IB Diploma has an Internal Assessment: the maths exploration, the science investigation, the economics portfolio, the history investigation, and so on. It's internally marked by the student's teacher, then externally moderated by the IB. It counts for a meaningful share of the subject grade. The exact weighting depends on the subject and level, so check the subject guide.
Here is the pattern that surprises families. A student who is comfortably on track in class, and does well in topic tests, submits an IA that comes back well below what anyone expected. Sometimes the moderated mark comes back lower again. The student understood the subject. Somewhere between the idea and the final draft, the marks went missing.
Why the IA is a different kind of test
An exam asks, "can you answer this question?" An IA asks, "can you design a piece of work, carry it out, and show the examiner every step of your thinking against a set of criteria?"
Those are different skills, and they are taught much less often. In class, a student practises answering. Few lessons are spent on choosing a question narrow enough to investigate properly, or on writing an evaluation that does more than list sources of error. Fewer still go on reading the criteria the way a moderator will.
That is why the IA catches out strong students in particular. Their exam technique carries them through tests. It doesn't transfer to a piece of extended, independent work.
Four places the marks go
When we look at an IA that has under-scored, the lost marks are almost always in one or more of these four places.
1 · The research question was too wide
This is the most expensive mistake, because everything after it inherits the problem. A question like "How does temperature affect enzymes?" is a topic, not an investigation. A question narrow enough to answer properly in the word limit, with a clear independent variable and a defined method, is what the criteria are built to reward. A wide question leads to a shallow method, a thin analysis and an evaluation with nothing specific to evaluate.
It is also the cheapest mistake to fix, as long as it's caught before the data is collected rather than after.
2 · It was written for the teacher, not the moderator
The teacher knows the student, sat through the practical, and remembers the conversation where the method changed. The moderator knows none of that. They have the document and the criteria, nothing else.
So a step that's obvious to the student, such as why a particular range was chosen, why an outlier was excluded, or what a graph is supposed to show, has to be on the page or it doesn't exist. Many IAs lose marks not for wrong thinking but for unwritten thinking.
This is also why the moderated mark can differ from the teacher's mark. Moderation checks that a school's marking matches the IB's standard, and it can adjust marks up or down. A student who writes for an informed outsider is far less exposed to that adjustment.
3 · The criteria were read once, at the start
Every subject's IA has published assessment criteria with descriptors for each mark band. Most students read them when the IA is introduced and never again. The criteria aren't a checklist to read once. They are the marking scheme, written in advance.
A useful habit is to take each criterion, find the descriptor for the top band, and ask honestly of the draft: "where on the page does it show this?" If you can't point to a paragraph, the mark isn't there yet.
4 · The deadline belonged to nobody
The IA runs alongside six subjects, the Extended Essay, TOK and CAS, mostly on internal school deadlines, and those deadlines come with far less noise than a test does. So it drifts. The data collection slips a few weeks. The analysis gets written in a hurry. The evaluation, the part that most needs time to think, is written the night before the draft is due.
This is the same pattern we see in homework, scaled up. Nothing goes wrong on any particular day. It simply never reaches the top of the list until it's late. We've written about this in Your child works hard and the marks haven't moved. The IA is the clearest Diploma example of work that's set and not yet attempted.
Who is allowed to help, and how
This deserves a straight answer, because families worry about it and they're right to.
The IA must be the student's own work. The IB's academic integrity rules apply to anyone who helps, including tutors. Schools also have their own rules on how much feedback a teacher may give on a draft. Check both your subject guide and your school's policy.
What legitimate support looks like:
- Explaining the criteria and what each mark band asks for
- Teaching the underlying skills: how to narrow a research question, how to process and present data, how to write a real evaluation
- Asking questions that make the student explain and defend their own choices
- Helping the student plan the timeline and keep to it
What it never looks like: choosing the question for them, writing or rewriting sections, or "fixing" the analysis. Apart from being against the rules, it doesn't work. A student who can't explain their own IA is exposed, and the skill the IA was meant to build never gets built.
What to check before the next draft
Whether your child is in DP1 or DP2, these questions take an evening and will tell you a lot.
- For each subject, where is the IA right now? Not started, question chosen, data collected, drafted, or submitted? And what are the school's internal dates for each?
- Can your child state the research question in one sentence, and explain why it's narrow enough to answer within the word limit?
- Have they read the current criteria for that subject in the last month? Can they point to where the draft meets the top band of each one?
- Would the draft make sense to a stranger? Ask them to read one section aloud as if they were the moderator. Gaps in reasoning are usually obvious when spoken.
- Is anyone tracking the IA timeline other than the student? If the only person who knows the next deadline is the person most likely to postpone it, that's the risk.
- Is anything else landing in the same weeks? DP1 students applying to US universities often sit the SAT in the same window as IA drafts. If so, plan both on one calendar. Our SAT page explains how we run SAT preparation alongside the Diploma.
How we run this
StudyWise teaches the IB Diploma one-to-one and online, and IA work is part of subject teaching rather than a bolt-on. We work through the IA with the student: the research question, the method, the analysis, and the criteria it's actually marked against. The student does the work; we teach the skills and keep the timeline honest. The same applies to the Extended Essay and TOK. More on how we support the DP core is on our IB tuition page.
We also count things. Classes attended against classes booked, work attempted against work set, and, for the IA, where it actually stands against the school's dates. Parents get a written update once a month. When an IA deadline starts slipping, you hear it while there's still time to do something about it, not after the draft is due.
For students coming into the Diploma from the MYP, a lot of IA readiness is built earlier: criterion-based thinking, command terms and the Personal Project. How we teach the MYP is on our MYP page. For students arriving from Cambridge or Edexcel IGCSE, the shift to criterion-marked coursework is often the biggest adjustment. More on that is on our IGCSE page.
Tell us the subject, where the IA stands and the school's next deadline. In one free diagnostic class we'll show you where the marks are likely to go, including when the answer is that the work is on track and you don't need us. Book a free diagnostic class or message us on WhatsApp.