How Are IB Internal Assessments Graded?

One of the most stressful parts of doing an Internal Assessment (IA) isn't just the research or the writing - it's not knowing how it'll actually be marked.

You've put in hours of work, but without understanding the grading criteria, it's hard to know if you're on track for top marks or missing something crucial. The uncertainty can be frustrating, especially when your IA contributes a significant chunk towards your final IB grade.

Read on to find out more about the grading process and what examiners are really looking for across different subjects.

Key Takeaways

• IAs are marked internally by your teacher, then sent to the IB for moderation to ensure consistency across schools worldwide.

• Grading criteria vary by subject, but most IAs assess things like personal engagement, critical thinking, methodology, and communication.

• IAs typically contribute 20-30% of your final grade in a subject, making them a vital opportunity to secure marks.

• Understanding the specific mark bands for your subject is the single most effective way to improve your IA score.

What Are IB Internal Assessments?

Internal Assessments (IAs) are pieces of coursework you complete during your IB Diploma Programme. You complete one IA for every subject you take. Unlike external exams, IAs are done over several weeks or months, giving you time to research, plan, and refine your work.

The format varies depending on your subject. 

In sciences, you'll conduct an experiment and write up your findings. 

In humanities, you might write an essay or analysis. 

In maths, you'll carry out an exploration applying maths concepts to a real-life scenario.

IAs are designed to let you explore a topic you're genuinely interested in, applying what you've learned in a more personal and creative way than a timed exam allows.

Who Grades Your IA and How?

Your teacher marks your IA first, using official IB criteria specific to your subject. They award marks based on detailed mark bands that describe what's expected at each level.

Once your teacher has marked your IA, a sample of work from your school is sent to the IB for external moderation. Then, an IB examiner reviews these samples to check that you’d have received the same grade had you studied at another IB school somewhere else in the world. The International Baccalaureate Organisation (opens in a new tab) (IBO) calls this the global standard.

General Assessment Criteria Across Subjects

While each IB subject has its own specific criteria, most IAs are assessed using similar core principles. Understanding these will give you a strong foundation, no matter what subject you're working on.

Personal Engagement

Examiners want to see that you've genuinely engaged with your topic. This means showing curiosity, initiative, and originality in your approach.

Personal engagement isn't just about saying, "I'm interested in this topic." It's about demonstrating it through: 

• Thoughtful research questions

• Creative methodology

• Unique perspectives

You'll score higher if your IA reflects independent thinking rather than just following a textbook formula.

Communication and Organisation

Clarity matters. Even the most brilliant ideas won't earn top marks if they're poorly explained or badly structured.

Your IA should be well-organised, with a logical flow that guides the reader from introduction to conclusion. Use headings, diagrams, and clear language to make your work easy to follow.

Critical Thinking and Analysis

This is often where students gain or lose the most marks. IB examiners aren't just looking for facts. They want to see you thinking critically about your topic.

• Can you evaluate evidence? 

• Do you recognise limitations in your methodology? 

• Can you analyse patterns and draw meaningful conclusions?

Stronger IAs go beyond description and show real depth of understanding. Don't just state what happened. Instead, explain why it matters.

Subject-Specific Criteria Breakdowns

Let's take a look at how grading works in different subject areas. 

Sciences (e.g. Biology, Chemistry, Physics)

Science IAs (opens in a new tab) focus heavily on methodical construction of experiments or solving scientific problems.

Examiners look for: 

• A clear, focused research question and a well-designed experiment

• Excellent data collection and analysis 

• Reliable results that are processed appropriately

• Well thought through conclusions 

Tip: Don't forget to evaluate your methodology. What were the limitations? How could your experiment be improved? Acknowledging weaknesses shows scientific thoroughness.

Maths

Maths IAs (opens in a new tab) reward mathematical reasoning and sophistication. 

Examiners look for: 

• A deep understanding of the concepts you're applying

• The application of maths to a real-life scenario

• The use of appropriate technology (like graphing software or statistical tools) 

Tip: The best Maths IAs connect abstract concepts to real and interesting problems. This shows engagement and makes your work more compelling.

Individuals and Societies (e.g. History, Geography, Economics)

Individuals and Societies (opens in a new tab) is a more varied subject group, including Business Management, Geography, and Digital Society. This means there’s more variety in the specifics of the individual subject IA requirements. However, they share some common assessment criteria: 

Examiners look for: 

• A clear argument backed up by evidence. 

  • You need a clear thesis and strong supporting evidence to back it up.

• Detailed source evaluation is critical. 

  • Where did your information come from? How reliable is it? Can you compare different perspectives or interpretations?

• A coherent structure. 

  • Your IA should build a logical case, with each paragraph contributing to your overall argument. Rambling or unfocused essays won't score well.

Language & Literature

Language and Literature IAs (opens in a new tab) focus on your ability to analyse texts closely and discuss how language creates meaning.

Examiners look for: 

• A deep understanding of literary or linguistic techniques

• Incisive discussion of their effects. 

• Close reading and detailed textual analysis.

Tip: Style and register matter too. Your writing should be formal, precise, and sophisticated, showing you can handle academic language confidently.

The Arts (e.g. Visual Arts, Theatre, Music)

Arts IAs (opens in a new tab) are unique because they assess both your creative work and your written reflection.

Examiners look for: 

• Evidence of experimentation, skill development, and artistic intention. 

• A clear creative journey shown in your portfolio or performance.

• Excellent self-reflection. You need to articulate your artistic choices, explain influences, and evaluate your successes and challenges. 

Tip: In some subjects, like Dance, you have the opportunity to work collaboratively. Consider this if working in a team plays to your strengths.

The Moderation Process Explained

Moderation can feel mysterious, but it's actually a straightforward three-step process. 

1. After your teacher marks your IA, the IBO selects a sample of work from your school to review.

2. An external examiner checks whether your teacher's marking matches IB standards. If your teacher has been too generous, marks may be scaled down. If they've been too harsh, marks may go up.

3. The adjustment applies to all students at your school, not just the sample. So if your teacher tends to mark strictly, moderation might actually improve your score.

Most schools have experienced teachers who understand the criteria well, so dramatic changes are rare. Still, it's worth knowing that your final mark isn't confirmed until after moderation.

Tips for Maximising Your IA Marks

Want to push your IA into the top mark bands? Here's how.

Start early. IAs take time. Rushing leads to weak research, shallow analysis, and careless mistakes. Give yourself weeks, not days.

Know your criteria inside out. Download the official grade descriptors (opens in a new tab) and refer to them constantly. They're your roadmap to success.

Ask for feedback. Your teacher can review drafts and point out where you're losing marks. Use this opportunity - it's allowed under IB rules.

Be specific and focused. Narrow, well-defined topics almost always score better than broad, ambitious ones. Depth beats breadth every time.

Proofread carefully. Spelling mistakes, unclear phrasing, and formatting errors make your IA look rushed. Take time to polish your final draft.

If you’re keen to maximise your IA marks, take a look at our ‘What Is a Good IB Score?’ article.

Frequently Asked Questions

Are all IB IAs graded in the same way?

No. Each subject has its own set of criteria and mark bands. While there are common themes (like critical thinking and communication), the specific expectations vary widely. Access the different IBO subject briefs (opens in a new tab) to discover more

Do IA marks affect my final grade significantly?

Yes. IAs make up 20-30% of your final grade in a subject. This makes them one of the most important pieces of work you'll complete during the IB. A strong IA can significantly boost your overall score.

Can my teacher help me improve my IA before submitting?

Yes, but there are limits. Your teacher can review drafts and give you feedback on how to improve. However, they can't write or edit your work for you.

Final Thoughts

Understanding how IB Internal Assessments are graded is useful to help you plan your time and focus your efforts. Once you know what examiners are looking for, you can work smarter and avoid common pitfalls.

IAs are a chance to showcase your knowledge, creativity, and critical thinking in a way exams never allow. With careful planning and a clear understanding of the criteria, you can earn the marks you deserve.

References

IBO - Assessment principles and practices—Quality assessments in a digital age (opens in a new tab)

IBO - Sciences in the DP (opens in a new tab)

IBO - Maths in the DP (opens in a new tab)

IBO - Individuals and Societies (opens in a new tab)

IBO - Languages and Literature (opens in a new tab)

IBO - Arts (opens in a new tab)

IBO - Subject Briefs (opens in a new tab)

IBO - Grade Descriptors (opens in a new tab)