- What Is an Internal Assessment in the IB?
- How Much Is the IA Worth?
- How IAs Are Marked and Moderated
- Internal Assessment Methods: The Main IA Formats
- Sciences IA Structure (Biology, Chemistry, Physics)
- Maths IA Structure (The Exploration)
- Individuals and Societies IA Structures
- Language A and Language B IA (Individual Orals)
- Arts, Computer Science and Design Technology
- The Research Question or Focus
- Methodology and Approach
- Results, Analysis and Interpretation
- Evaluation and Critical Reflection
- Formatting, Word Limits and Presentation
- Planning Your IA: A Realistic Timeline
- Common IA Mistakes Across Subjects
Quick Answer
An IB internal assessment (IA) is the coursework part of a Diploma Programme subject. Your teacher marks it against the IB's published criteria, then the IB moderates a sample from your school and can adjust everyone's marks. Most IAs are worth 20-30% of the subject grade. The format depends on the subject: a scientific investigation, a maths exploration, an oral, a portfolio or a research project.
What You'll Learn
- An IA is coursework marked by your teacher and moderated by the IB, not an exam
- Most IAs are worth 20-30% of the subject grade, often more at SL than at HL
- Moderation can move marks up or down for every student in the group, not just those sampled
- Formats differ: investigations in the sciences, an exploration in maths, orals in languages, portfolios and projects in humanities
- Several subjects have new guides for 2026 to 2028 exams, so check which version your class follows
What Is an Internal Assessment in the IB?
In education generally, internal assessment means work that is marked inside the school rather than by an external examiner. In the IB Diploma Programme, the internal assessment, usually called the IA, is the coursework component of each subject. You complete it during the course, your teacher marks it against criteria published in the subject guide, and the IB checks that marking through moderation. Almost every DP subject has one. The IA lets you show skills that a timed exam cannot test, such as designing an investigation, collecting data, researching a real organisation or speaking about texts. It counts towards your final 1 to 7 grade alongside the exam papers.
- IA: marked by your teacher, moderated by the IB, counts towards the subject grade
- External assessment: exam papers and some coursework, such as the extended essay and the TOK essay, marked by IB examiners
- The TOK exhibition is internally assessed too, but it belongs to the core, not to a subject
- The extended essay is a separate core requirement and cannot be the same piece of work as an IA
How Much Is the IA Worth?
Most IAs are worth between 20% and 30% of the final subject grade. In many subjects the share is higher at SL than at HL, because HL students sit an extra exam paper that takes up part of the weighting. These figures apply to exams in 2026 and 2027 unless a cohort note says otherwise.
- Biology, chemistry and physics: scientific investigation, 20% at SL and HL
- Maths (analysis and approaches, and applications and interpretation): exploration, 20% at SL and HL
- Environmental systems and societies: individual investigation, 25% at SL, 20% at HL
- Computer science: computational solution, 30% at SL, 20% at HL
- Design technology from May 2027: design project, 40% at SL, 30% at HL
- Economics: portfolio of three commentaries, 30% at SL, 20% at HL
- Business management: business research project, 30% at SL, 20% at HL
- History: historical investigation, 25% at SL, 20% at HL
- Geography: fieldwork written report, 25% at SL, 20% at HL
- Language A (literature, and language and literature): individual oral, 30% at SL, 20% at HL
- Language B: individual oral, 25% at SL and HL
- Psychology from May 2027: research proposal, 30% at SL, 20% at HL
Pro Tip
A 20% IA is worth as much as a whole exam paper in many subjects, and you control the time, the topic and the drafting. It is usually the most predictable part of your grade.
How IAs Are Marked and Moderated
Moderation is what makes a teacher's mark comparable across thousands of schools. It is also why the mark your teacher gives you is provisional until results day.
- 1Your teacher marks every IA in the class using the subject's criteria and a best-fit approach: for each criterion, they choose the level descriptor that best matches the work.
- 2If more than one teacher marks the subject at your school, they standardise their marking first.
- 3The school submits all the marks to the IB and uploads a sample of students' work for moderation.
- 4An IB moderator re-marks the sample and compares their marks with your teacher's.
- 5If the teacher's marking is consistently too generous or too harsh, the IB adjusts the marks of every student in that group, including those not in the sample. Marks can go up as well as down.
- 6The moderated IA mark is combined with your exam marks to produce your final 1 to 7 subject grade.
Watch Out
Do not rely on a generous internal mark. Aim at what the criteria describe, because the moderator marks against the same descriptors your teacher used.
Internal Assessment Methods: The Main IA Formats
The IB uses several different methods of internal assessment, chosen to suit each subject. Knowing which type you face tells you what kind of structure and evidence the criteria expect.
- Investigation with your own data: the sciences' scientific investigation and the geography fieldwork report
- Mathematical exploration: a written piece on a mathematical topic you choose, in maths
- Source-based investigation: the history historical investigation
- Commentary portfolio: three short commentaries on news articles, in economics
- Research project on a real organisation: the business management business research project
- Individual oral: a recorded oral with your teacher, in Language A and Language B
- Research proposal: the new psychology IA from May 2027
- Product or solution development: computer science and design technology
- Practical and creative work: in the arts, much of the internal assessment is practical rather than a written report
Sciences IA Structure (Biology, Chemistry, Physics)
Biology, chemistry and physics share one IA under the guides first assessed in 2025: a scientific investigation in which you gather and analyse data to answer your own research question. The written report has a maximum of 3,000 words and the IB recommends about 10 hours for the task. It is marked out of 24 using four equally weighted criteria, so a structure that follows the criteria works well.
- 1Research design (6 marks): a focused research question, the scientific background, and a methodology that explains your variables, controls and how you will collect enough reliable data
- 2Data analysis (6 marks): processing raw data correctly, handling uncertainties, and presenting it in clear tables and graphs
- 3Conclusion (6 marks): a direct answer to your research question, justified by your analysis and compared with accepted scientific context
- 4Evaluation (6 marks): specific weaknesses and limitations of your method and data, with realistic improvements
Pro Tip
Charts, data tables, equations, calculations, citations and the bibliography do not count towards the 3,000 words, so spend your words on explaining method, analysis and evaluation.
Maths IA Structure (The Exploration)
In Mathematics: analysis and approaches and Mathematics: applications and interpretation, the IA is an exploration: a written piece of about 12 to 20 pages on a topic you choose. It is not a lab report. It reads more like a guided mathematical argument with an introduction, a developing body and a conclusion. Under the current guides, used for exams up to November 2028, it is marked out of 20 against the five criteria below. Students who start the course in August 2027 (first exams in May 2029) move to new guides with four criteria, the same at SL and HL: problem specification (4 marks), abstraction (6), computation (4) and interpretation (6), still out of 20.
- Presentation (4 marks): a coherent, well-organised and concise exploration
- Mathematical communication (4 marks): correct notation, terminology, symbols and labelled graphs
- Personal engagement (3 marks): your own questions, choices and ideas, not a textbook summary
- Reflection (3 marks): critical thinking about your results, methods and limitations
- Use of mathematics (6 marks): relevant mathematics at the level of your course, used correctly and with understanding; descriptors are more demanding at HL
Individuals and Societies IA Structures
Group 3 subjects have the widest range of IA formats, so structure varies most here. These are the main ones for 2026 and 2027 exams.
- Economics: three commentaries of up to 800 words each, each on a news article from a different unit, source and key concept; marked out of 45
- Business management: one business research project of up to 1,800 words on a real organisation, using a key concept and 3 to 5 supporting documents; marked out of 25
- History: a historical investigation of up to 2,200 words in three sections: identification and evaluation of sources (6 marks), the investigation (15 marks) and a reflection (4 marks), for 25 marks. The new History guide is first assessed in May 2028, so 2026 and 2027 students follow this structure
- Geography: a fieldwork report of up to 2,500 words based on primary data you collect, with a fieldwork question linked to the syllabus
- Psychology: students sitting exams in 2026 complete the experimental study from the previous guide. From May 2027 the IA is a research proposal of up to 2,200 words, marked out of 24
- Global politics: an engagement activity in which you engage with a political issue and write it up; check the version of the guide your school follows
Language A and Language B IA (Individual Orals)
In languages the IA is spoken, not written, so structure means how you plan the oral rather than how you lay out a report.
- Language A (literature, and language and literature): the individual oral lasts up to 15 minutes, a 10-minute response followed by 5 minutes of questions from your teacher. You examine how a global issue of your choice is presented in extracts from two texts you have studied; in language and literature, these are one literary work and one non-literary body of work. It is marked out of 40 across four criteria of 10 marks each
- Language B: an individual oral with your teacher, worth 25% at both levels. At SL it starts from a visual stimulus linked to a theme of the course; at HL it starts from an extract from one of the literary works you have studied
- Plan the oral with a clear line of argument and a small number of well-chosen examples, and practise to time
Arts, Computer Science and Design Technology
Arts subjects assess much of their coursework internally through practical or creative work, and their components vary widely, so follow your subject guide closely. Computer science and design technology both have new guides first assessed in May 2027, with revised IAs. If you sit exams in 2026 you follow the previous guide; if you sit them from May 2027 you follow the new one. Your teacher can confirm which applies to your class.
Watch Out
Online advice is often written for an older guide. Before you follow any IA template, check the first assessment year of the guide it was written for.
The Research Question or Focus
Almost every written IA starts from a focused question or aim. A good one is narrow enough to answer properly within the word or page limit, clearly connected to your subject's syllabus, and answerable with the evidence you can realistically get.
- Sciences: a question about how one independent variable affects one dependent variable, or about a relationship in a data set
- Maths: a clearly stated aim for the mathematics you will explore
- History: a question about the past that you can answer from a range of sources
- Economics: your article sets the focus, so the issue it reports is effectively your question
- Business management: a question about a real issue facing one named organisation
Watch Out
Avoid questions with an obvious yes or no answer. The best questions invite analysis and a judgement, which is what the higher markbands reward.
Methodology and Approach
For IAs built on an investigation, explain what you did and, more importantly, why you did it that way. This is where you show that your approach suits the question.
- 1Explain your overall approach and why it suits the question
- 2Detail the methods, materials, sources or documents you used
- 3Show how you controlled variables or made your evidence reliable
- 4Address safety, ethical or environmental issues where relevant
- 5Acknowledge the limitations of your chosen approach
Pro Tip
In the sciences, write the method in enough detail that someone else could repeat it. In history, business management and economics, the equivalent is explaining why your sources or documents are the right evidence.
Results, Analysis and Interpretation
Raw results or facts earn little on their own. Marks come from interpreting them and connecting them back to your question.
- Present data clearly, with labelled tables, graphs or diagrams
- Explain what your results show, not just what they are
- Link each finding back to your research question
- Use subject terminology accurately
- Identify patterns, trends, anomalies or competing interpretations
- Explain the significance of your findings for the wider topic
Evaluation and Critical Reflection
Evaluation is where many students lose marks by being vague. Strong evaluation names specific strengths and weaknesses of your evidence and method and explains how they affect your conclusion.
- Judge the reliability and validity of your data or sources
- Name specific limitations, not generic ones such as human error
- Suggest realistic improvements that address those limitations
- Consider other interpretations or perspectives
- Say how confident your conclusion is, and why
Watch Out
Avoid generic statements like I could have collected more data. Say which data, why it would help and how you would collect it.
Formatting, Word Limits and Presentation
Clear presentation helps your teacher and the moderator find the evidence for each criterion, and in some subjects presentation is marked directly.
- Stay within the word, page or time limit. In many subjects, including Economics, moderators do not read or credit work beyond it
- Check what your subject excludes from the word count: diagrams, data tables, equations, citations and the bibliography are often excluded, while definitions and quotations usually count
- Use headings that follow the logic of the criteria
- Number pages, label every table, graph and diagram, and reference sources consistently
- Include a bibliography in a consistent referencing style
- Put anything that earns marks in the main body, not in footnotes or an appendix
Planning Your IA: A Realistic Timeline
Schools set their own internal IA deadlines, well before the date they must submit marks and samples to the IB. Work back from your school's final deadline.
- 1Read the criteria for your subject before choosing a topic
- 2Choose a topic and agree it with your teacher
- 3Plan your method, sources or documents
- 4Collect your data or evidence
- 5Write a full draft. In most subjects your teacher can give feedback on one draft but must not edit it
- 6Revise and submit the final version, which you then confirm as your own authentic work
Common IA Mistakes Across Subjects
These problems appear in every subject and are easy to avoid if you check for them early.
- Starting before reading the assessment criteria
- A research question too broad to answer within the limit
- Describing instead of analysing
- Going over the word or time limit
- Generic evaluation that could apply to any IA
- Following a template written for an older version of the subject guide
- Leaving the draft so late that there is no time to act on feedback