IB Internal Assessment (IA): Scoring Guide
The IA rewards method, not talent. Here's a step-by-step way to move from topic to submission without leaking marks.
The Internal Assessment (IA) is the investigation required in most IB subjects, and it's worth 20–30% of your final score. Unlike the external exams (Papers), the IA is something you can build up methodically over time — which is exactly why it's one of the most controllable parts of any strategy for lifting your final score. Approach it haphazardly, though, and you'll lose marks against the criteria.
How IA marks actually work
IAs aren't graded on how "interesting" they are, but on how closely they meet the assessment criteria for that subject. Common threads across subjects include:
- Clarity and focus of the research question (RQ)
- Validity of method and analysis
- Depth of interpretation and discussion
- Honesty of the evaluation (limitations and improvements)
- Presentation, referencing and word count
The first thing to do is open your subject's Subject Guide and print the criteria. Writing before you know where marks are awarded is the single biggest way to lose them.
Choosing a topic and research question
Around 80% of IA success comes down to RQ design. The classic mistake is a question that's too broad — the same first hurdle you'll meet in the longer-form Extended Essay (EE).
- Pick a broad area you're interested in (e.g. exercise and heart rate)
- Narrow the subject, conditions and timeframe (who, under what conditions, how much)
- Shrink it to something you can measure and analyse yourself
- Phrase it as a single question
A good RQ can't be answered in one sentence but fits the word count. Too narrow and the analysis is thin; too broad and it loses focus. Subject-specific examples — such as writing a Math IA — make this easier to gauge against each subject's own criteria.
A workable timeline
| Stage | What to do | Where students slip |
|---|---|---|
| 1. Plan | Lock topic, RQ and method | Too-broad RQ corners you later |
| 2. Collect | Gather data / sources | Not enough for the criteria |
| 3. Analyse | Process and interpret results | "Listing results" with shallow discussion |
| 4. Write | Draft to the structure | Over word count, weak referencing |
| 5. Refine | Self-mark against criteria | Run out of time before submission |
The most important habit is not rushing Stage 1. If you start collecting before the RQ and method are settled, you'll redo everything later.
Common mistakes and fixes
- Results listed with no discussion → always go one level deeper: "why" and "what this means".
- Sloppy evaluation (limitations) → specific limitations and improvements fill criteria you'd otherwise miss; the habit of questioning your evidence and its limits is exactly what TOK (Theory of Knowledge) trains.
- Referencing gaps → standardise your citation format before submitting; plagiarism flags are fatal.
- Over the word count → in some subjects, anything over the limit isn't marked. Write to cut.
The IA rewards knowing the "right shape." If your RQ won't settle or you're unsure how to fill the criteria, a single review at the design stage by a tutor who's been through the IB can save you a lot of wasted detours.