IB Psychology IA: Criteria, Word Count & How to Pass

By Michael Thompson · Education Specialist; 10 years teaching the IB at Bromsgrove School · Published 4 September 2026 · Updated 6 October 2026

From May 2027, the IB Psychology IA is a research proposal. You design a study to investigate a population of interest, using one of the four research methods from your class practicals, and you do not carry it out. Your teacher marks it, the IB moderates a sample, and the task is the same at SL and HL. This guide explains what the proposal involves, what each of the four criteria rewards, the 2,200-word limit, and how to handle ethics, sampling and your data-collection tool.

Key Takeaways

• A proposal, not an experiment: You design a study and justify every choice, but you do not collect data. The IB describes the task as a research proposal.
• One of four methods: Your design must use one of the four research methods from the class practicals. The subject guide lists experiment, interview (including focus groups), observation, and survey or questionnaire.
• 24 marks across four criteria: The IB's subject guide has four criteria worth 6 marks each: Introduction, Research methodology, Data collection and Discussion.
• Word limit: 2,200: The proposal must not exceed 2,200 words, and examiners stop reading at the limit. References and appendices do not count.
• Same task at SL and HL: Both levels write the same proposal. What differs is how much it counts towards the final grade: 30% at SL and 20% at HL.
• Ethics still counts: You never meet participants, but your design must still protect them. The Research methodology criterion asks you to explain the ethical considerations, linked to your own study.

In This Article

1. What the IB Psychology IA actually is
2. IB Psychology internal assessment criteria explained
3. Choosing a research problem and a population of interest
4. The ethics checklist every IB Psychology IA needs
5. Data collection: designing your own tool
6. IB Psychology IA format and word count
7. Common mistakes that cost marks - and how to avoid them
8. What to do next

1. What the IB Psychology IA actually is

For students first assessed in May 2027, the IB Psychology IA is a research proposal. According to the IB's psychology updates page, you design a research proposal to investigate a population of interest using one of the four research methods used in the class practicals. You plan the study in detail and justify it, but you do not run it: there are no participants to recruit, no data to collect and no results to report.

Because nothing is carried out, the proposal is judged on the quality of your thinking: whether the research problem matters, whether the method fits it, whether the sample represents the population you care about, and whether the procedure is ethical and workable. The subject guide also lets you propose things a DP student could not normally do, such as interviewing people with depression or following participants over several years. Ambition is welcome, but the design must still be ethical, written as if it had to pass an ethics committee, and the guide is clear that the marks are for justifying your methodological decisions, not for designing the perfect study.

Marking works in two stages. Your teacher marks the proposal first, then the IB externally moderates a sample of each school's work to check that the criteria are being applied consistently, as with all internally assessed work in the Diploma Programme. If your teacher's marks do not match the descriptors, the moderated marks can move down (or up).

One detail that catches students out: HL and SL students complete the same IA. There is no extended or separate HL version of the task. The differences between the levels sit in the exam papers and in how much the IA counts towards the final grade (30% at SL, 20% at HL); the IB Psychology syllabus guide covers both.

November 2026 candidates only: you are on the previous course, and your IA is the experimental study: a replication of a published experiment, written up in 1,800-2,200 words and marked out of 22 (Introduction 6, Exploration 4, Analysis 6, Evaluation 6). The rest of this guide describes the new research proposal and does not apply to you.

2. IB Psychology internal assessment criteria explained

The criteria come from the IB's Psychology guide (first assessment 2027). The proposal is marked out of 24, across four criteria worth 6 marks each, and each criterion has three bands of descriptors (1-2, 3-4 and 5-6 marks). The table summarises what the top band asks for; your teacher has the full descriptors.

The marking is criterion-related: you are judged against fixed descriptors, not ranked against your classmates, so a strong cohort does not push your mark down.

The Introduction builds on two pieces of relevant research. The guide asks for a brief literature review of their findings and key conclusions, without procedural detail unless it matters to your design, and the lowest band describes an Introduction with only one piece of research. The guide does not require the research to be peer-reviewed, and qualitative and quantitative research are equally acceptable. Read widely first, then choose the two studies that genuinely shape your design and explain how each one does.

Notice too that three of the four criteria are about design. Most of your words should go on the method, the sample, the tool and their justification, not on background.

3. Choosing a research problem and a population of interest

The biggest decision in the proposal is which problem to investigate, and in whom. Get those two right and the rest of the design follows from them.

Start with a real-world problem

A good proposal starts from a question that matters outside the classroom: for example, why some students stop exercising when exam pressure rises, how night-time phone use relates to sleep in teenagers, or how young carers manage stress. A problem like this tells you what to measure and why the answer would be useful. Linking it to one of the course's four contexts (health and well-being, human development, human relationships, or learning and cognition) makes relevant research easier to find.

Define the population of interest

The IB's description of the task centres on a population of interest, so be specific. "Teenagers" is too broad. "16 to 18-year-olds in international schools who use social media for more than three hours a day" gives you a population you can sample from and a reason for every later choice.

Match the method to the question

Each of the four methods answers a different kind of question:

• Experiment - when you want to test whether one variable causes a change in another, and you can manipulate it ethically.
• Observation - when you want to record behaviour as it naturally happens.
• Survey or questionnaire - when you need attitudes or self-reported behaviour from a large sample.
• Interview or focus group - when you want depth: people's experiences in their own words.

Justify your choice against the alternatives. Saying why you did not use an experiment, for example, shows you understand what each method can and cannot tell you.

Plan a realistic sample

Name your sampling technique (random, stratified, opportunity, purposive and so on), say how you would recruit participants, and explain how the sample would represent your population. If the most practical sample would be biased, say so and explain what you would do about it. That honesty is stronger than a sample that looks perfect on paper but could never be recruited.

4. The ethics checklist every IB Psychology IA needs

You will not meet any participants, but your proposal has to show how you would protect them. The Research methodology criterion asks you to explain the ethical considerations and link them to your investigation, and the guide says the proposal should be written as if it had to pass an ethics committee. A design that would harm or deceive its participants is not a credible proposal however clever it is.

What your proposal should plan for

• Informed consent - how you would obtain it, and from whom. If your population includes under-16s, plan for consent from a parent or guardian as well.
• Right to withdraw - how participants would know they can leave at any point without penalty, and have their data removed.
• Debriefing - what participants would be told afterwards, especially if anything about the aim is concealed during the study.
• Anonymity and confidentiality - how data would be stored, who could see it, and how participants would be told this in advance.
• Protection from harm - how you would notice distress and what support you would point people to.

Designs to avoid

• Procedures likely to cause psychological distress, even mild or temporary
• Deception that a debrief could not undo
• Vulnerable groups, such as clinical populations or young children, where you cannot justify the safeguards
• Physiological measures or settings that would need medical supervision
• Animals, or anything participants would eat or drink (the guide rules both out, though self-reported diet is fine)

The guide also bars some topics outright as the focus of the IA: abuse, self-harm (including suicide), pornography or sexual acts, and serial killers or torture. Ask your teacher about anything else that could be sensitive where you live.

The population of interest raises its own ethical questions. A proposal about stress in young carers, for example, needs to explain how you would avoid adding to that stress. Generic ethics paragraphs copied from a template are easy to spot, so tie each safeguard to your actual participants.

What a consent form and debrief should cover

The guide does not require a consent form, standardised instructions or a debrief: the only material you must submit is your data-collection tool. Sketching what they would cover can still help you think the ethics through.

A consent form should include:

• Study title and researcher name
• A plain-language description of what taking part involves
• A right to withdraw statement ("at any point, without penalty")
• A data anonymity statement
• A signature line and date

A debrief should include:

• The true aim of the study
• Why any concealment was necessary
• Confirmation that the participant's data will be stored securely and anonymised
• Contact details for follow-up questions or support

5. Data collection: designing your own tool

The Data collection criterion asks for one tool that you create to measure behaviour. It needs at least five items (a questionnaire needs at least five questions, for example), and a copy goes in the appendix. You can draw on existing measures, but you have to explain the decisions you made in building it. What the tool looks like depends on your method:

• Experiment - the measure of your dependent variable, such as a short test or rating scale with at least five items.
• Observation - a behaviour checklist or coding scheme, with a clear definition of each behaviour and how often it is recorded.
• Survey or questionnaire - your items, the response scales, and the order in which questions appear.
• Interview or focus group - an interview schedule: the questions, the follow-up prompts, and how answers would be recorded.

Operationalising variables: why specificity is the point

Operationalising means turning an abstract psychological construct into something specific and measurable. "Memory" is a construct. "The number of words recalled correctly from a 20-item list after a 30-second delay" is an operationalised variable. The same applies to every method: in a questionnaire, which items measure "stress", and how are they scored? In an observation, what exactly counts as "aggressive behaviour"? The guide lists identifying and operationalising variables among the decisions you can explain under this criterion.

Anticipate the problems

For each part of your tool, ask what could go wrong: leading questions, social desirability, observers disagreeing, participants guessing the aim. Then say how your design limits each risk, for example by piloting the tool, using two observers, or wording items neutrally.

Planning the analysis

Because you do not collect data, you will not run statistics, and none of the four criteria asks for an analysis plan. A sentence on how you would analyse the data can show that your tool answers your question, but spend your 2,200 words on what the criteria reward.

6. IB Psychology IA format and word count

The proposal must not exceed 2,200 words. The guide tells examiners to stop reading when the limit is reached. References and appendices do not count towards it, but both must be included: the appendix holds your data-collection tool, and the references are required for academic integrity even though they are not marked. The title page gives the title, your IB student code, the date of submission and the word count.

Stay under it. Anything past 2,200 words is not read, and a proposal that runs long usually means the method and tool sections are padded with background.

A structure that follows the criteria

The guide asks you to structure the proposal under the four criterion headings, which also makes it easy for your teacher, and a moderator, to find what each criterion asks for:

1. Introduction - the problem, the population of interest, the two studies you build on, and your aim
2. Research methodology - the method and why, sampling and participants, procedure, ethical safeguards
3. Data collection - your tool, the decisions behind it (including how it operationalises your variables), and the challenges you anticipate
4. Discussion - potential findings and their implications for policy or practice, researcher bias, and one additional research method

Referencing

APA style is the usual convention in psychology. Whatever style your school uses, apply it consistently, because the studies you cite carry your Introduction and inconsistent referencing suggests careless reading. References are not marked, but the guide requires them, and research in another language needs a translated title.

7. Common mistakes that cost marks - and how to avoid them

The research proposal is new, so there are no moderator reports on it yet. The mistakes below follow from what the task asks for and from how research proposals usually go wrong.

Running the study anyway. Writing up results you collected, or describing findings as if they had happened, misreads the task. Your Discussion should say what you expect to find and why.

A population that is too vague. "People" or "students" gives you nothing to justify your sample, your method or your ethics against.

A method that does not fit the question. Proposing a survey to test a cause-and-effect claim, or an experiment to explore lived experience, undermines every later section.

Reusing someone else's tool. The criterion rewards a tool you have created and the decisions behind it, so build your own rather than lifting a published questionnaire whole. Linking it to existing measures is fine if you explain why.

Generic limitations. "The sample might be small" says nothing on its own. Name the specific limitation and the effect it would have. Here is an illustrative example, written for this guide rather than taken from a student's work: "Recruiting through a single school's sixth form would over-represent academically engaged students, so the proposed study could overestimate how well 16 to 18-year-olds cope with exam stress."

Ethics as an afterthought. A template paragraph on consent that never mentions your actual participants shows you have not thought about them.

Summarising too much research. The Introduction builds on two pieces of research. Explain how each one shapes your design rather than listing many.

8. What to do next

Most students delay choosing a research problem until the pressure builds, then pick something vague and regret it. Every other part of the proposal, from the population to the method to the tool, depends on that choice, so make it early.

This week, do two things. First, ask your teacher for the full IA criteria from the subject guide, so you can check each part of your plan against the level descriptors.

Second, write one paragraph naming the real-world problem, your population of interest and the method you would use, with one sentence on why that method fits. That paragraph becomes the spine of your proposal. For how the IA fits into the rest of the course, see our IB Psychology syllabus guide.

FAQ

What is the IB Psychology IA?

From May 2027, the IB Psychology IA is a research proposal: you design a study to investigate a population of interest using one of the four research methods from your class practicals, but you do not carry it out. Your teacher marks it and the IB moderates a sample.

When is the IB Psychology IA due?

The submission deadline is set by your school and coordinated with the IB's moderation calendar - typically in the first term of Year 2 of the Diploma Programme; check your school's internal deadline, which will fall before the IB's own moderation window.

What is the word count for the IB Psychology IA?

The proposal must not exceed 2,200 words, and examiners stop reading at the limit. References and appendices are not included in the count.

Is the IB Psychology IA the same for HL and SL?

Yes. HL and SL students complete the same research proposal task. The differences between the levels are in the exam papers and in how much the IA counts towards the final grade: 30% at SL and 20% at HL.

Do you collect data for the IB Psychology IA?

No. The IA is a proposal, so you design the study, including your own data-collection tool, and explain what you would expect to find, but you do not recruit participants or collect data.

How does ethics affect the IB Psychology IA mark?

The Research methodology criterion asks you to explain the ethical considerations in your study and link them to your investigation, so your proposal needs to show how you would protect participants through consent, the right to withdraw, debriefing and confidentiality, tied to your specific population.

References

• Psychology updates - International Baccalaureate - https://ibo.org/university-admission/latest-curriculum-updates/psychology-updates/