The IB Physics IA is one scientific investigation: you answer your own research question with data you gather and analyse, and write it up in at most 3,000 words. It is worth 20% of the final grade at SL and HL, and is marked out of 24 on four criteria worth 6 marks each: research design, data analysis, conclusion and evaluation.
By Archie Dyer, founder of Cognivia Tutoring · Last checked 16 October 2026
20% of the final gradeThe same weighting at SL and HL.
At most 3,000 wordsTables, graphs, equations and references not counted.
Marked out of 24Four criteria, 6 marks each, by your teacher.
Moderated by the IBSame criteria for SL and HL.
Same task in ChemistryAnd in Biology: one IA requirement for all three.
What is the IB Physics IA?
The IB calls it “an open-ended task in which the student gathers and analyses data in order to answer their own formulated research question”. It is the only internal assessment in the course, and the IB says “the IA requirement is the same for biology, chemistry and physics”, so everything on this page applies to the Chemistry IA as well.
Weighting
20% of the final grade, at both SL and HL.
Time
The IB recommends about 10 hours of teaching time for the work.
Length
“The maximum overall word count for the report is 3,000 words.”
Not counted
Charts and diagrams, data tables, equations, formulas and calculations, citations, the bibliography and headers.
At the start
The title, your IB candidate code (and those of any group members) and the number of words. No cover page or contents page is required.
Data
The investigation “must involve the collection and analysis of quantitative data”, supported by qualitative observations where appropriate.
Marking
Marked by your teacher out of 24 and moderated by the IB.
The data does not have to come from the lab. The IB lists five approaches, which can be used alone or together: hands-on practical work, fieldwork, a spreadsheet for analysis and modelling, data extracted from a database, and a simulation. The research question “should be of interest to the student”, but it does not need to go beyond the physics in the syllabus.
Source: IB Diploma Programme Physics guide (first assessment 2025), “Internal assessment”. The guide is published to schools through the IB’s Programme Resource Centre, so your teacher has the current version. Checked on 16 October 2026.
What are the four IA criteria, and what earns full marks?
Each criterion is worth 6 marks, or 25% of the IA. The right-hand column is a summary of the IB’s top-band (5–6 mark) descriptor.
The four IB Physics internal assessment criteria, their marks and what the top band asks for
Criterion
Marks
What the top band asks for
Research design
6
The research question is described “within a specific and appropriate context”, the methodological choices are explained, and the method could be reproduced from the report.
Data analysis
6
Recording and processing that is “both clear and precise”, an appropriate consideration of uncertainties, and processing carried out “appropriately and accurately”.
Conclusion
6
A conclusion that is justified, “fully consistent with the analysis presented”, and compared with the accepted scientific context.
Evaluation
6
The report “explains the relative impact of specific methodological weaknesses or limitations”, and explains realistic improvements relevant to them.
Two things about how the marking works are worth knowing. Teachers use a best-fit approach, so a report does not have to meet every part of a descriptor to earn its marks. And the IB is explicit that “the highest level descriptors do not imply faultless performance”: full marks are meant to be achievable.
Source: IB Physics guide (first assessment 2025), “Internal assessment criteria—SL and HL”. Checked on 16 October 2026.
What makes a good IA research question?
The IB’s clarification is specific. A research question with context “should contain reference to the dependent and independent variables or two correlated variables, include a concise description of the system in which the research question is embedded, and include background theory of direct relevance.”
The “methodological considerations” the criterion asks you to explain are, in the IB’s list:
how you measure the independent and dependent variables, or which database or model you use and how you sample it;
the range, interval and repetition of measurements, and their precision;
which variables you control, and how;
any safety, ethical or environmental issues.
How I would approach it, as my own advice rather than the IB’s: pick a question where physics predicts a relationship, so that the conclusion has something definite to be compared with. Choose a range wide enough to show the shape of that relationship, and think about how you will draw the graph before you collect anything. A relationship that can be turned into a straight-line graph makes the analysis, the uncertainties and the comparison with theory much easier to do well.
Quotation and list from the “Clarifications for research design” in the IB Physics guide (first assessment 2025). Checked on 16 October 2026.
Why do uncertainties matter so much?
Because they run through three of the four criteria. Data analysis asks for “an appropriate consideration of uncertainties”. The conclusion criterion says a fully consistent conclusion “requires the interpretation of processed data including associated uncertainties”. And the weaknesses examined in the evaluation include “the precision of measurement or the variation in the data”.
The IB also separates two qualities that are easy to blur:
Clear means “the method of processing can be understood easily”.
Precise means “following conventions correctly, such as those relating to the annotation of graphs and tables or the use of units, decimal places and significant figures”.
The evaluation works the same way. Weaknesses that are “general to many methodologies” score in the bottom band; the top band needs specific weaknesses, the relative impact of each, and realistic improvements that answer them. Limitations can also be about scope: the range of data you collected, the system you studied, or the assumptions you made.
Source: the data analysis, conclusion and evaluation criteria and their clarifications in the IB Physics guide (first assessment 2025). Further guidance on uncertainties is in the IB’s Physics teacher support material. Checked on 16 October 2026.
Can you do the IA in a group?
Partly. Collaborative work is optional, groups can be no larger than three, and each student still answers their own research question and writes their own report. The IB’s rules are:
each group member manipulates a different independent variable, or the same independent variable with a different dependent variable, or different data from a larger shared data set;
“A student must not present the same set of raw data as another student.”
“A report by the group is not permitted. All authoring, including the description of the methodology, must be done individually.”
Working alone, you can still get help from classmates while collecting data. Whichever route you take, your teacher has to make sure you understand the difference between collaboration and collusion.
Source: “Methodology for individual work” and “Methodology for collaborative work” in the IB Physics guide (first assessment 2025). Checked on 16 October 2026.
Who can help with the IA, and how much?
Your teacher is your first source of help, and the IB says students “must not be penalized for seeking guidance”. The rule on drafts is precise: teachers “should read and give advice to students on one draft of the work”, giving oral or written advice on how it could be improved, “but not edit the draft”. The next version handed in is the final one.
Two academic integrity points matter as much as the criteria:
The work must be entirely your own. Each student confirms that the work is authentic, and once the final version is submitted it cannot be withdrawn.
Referencing is required. The IB states: “Omitted or improper referencing will be considered to be academic malpractice.”
Before you get any outside help with IA work, check with your teacher. Schools set their own rules on this, and your teacher has to authenticate the final report as yours.
How Cognivia can help
Cognivia Tutoring is independent and has no connection with the IB. Archie Dyer, a second-year Theoretical Physics student at UCL who scored 7 in HL Physics, helps in two ways. Lessons cover the physics and the skills behind the IA: uncertainties, graphs and linearisation, and the theory your research question rests on. They cost £45 an hour online on Google Meet or £55 in person around Marylebone, London. Coursework feedback gives written comments on your own draft within 5 days: £50 up to 750 words, £100 up to 1,500 words and £200 up to 3,000 words, the last two with a 30-minute call. Archie never writes any part of the work. More on IB Physics tutoring and IB Chemistry tutoring.
Source: “Internal assessment” and “Referencing and academic integrity” in the IB Physics guide (first assessment 2025). Checked on 16 October 2026.
FAQ
IB Physics IA questions, answered
The report has a maximum of 3,000 words. Charts, diagrams, data tables, equations, calculations, citations, the bibliography and headers are not included in the word count.
20% of the final grade, at both Standard Level and Higher Level. It is marked out of 24 by your teacher and moderated by the IB.
Four criteria worth 6 marks each: research design, data analysis, conclusion and evaluation, for a total of 24. The same criteria are used at SL and HL.
No. The task, the 3,000-word limit, the 20% weighting and the assessment criteria are the same at Standard Level and Higher Level.
Yes. The IB lists hands-on practical work, fieldwork, spreadsheet analysis and modelling, data extracted from a database and simulations as approaches that can be used alone or together. The investigation must still involve collecting and analysing quantitative data.
You can work in a group of up to three, but each student answers their own research question, must not present the same raw data as another student, and writes their own report. A group report is not permitted.
Yes. The IB states that the IA requirement is the same for biology, chemistry and physics: one scientific investigation, written up in at most 3,000 words, worth 20% and marked on the same four criteria.
A tutor can teach the physics and the skills behind it, such as uncertainties and graph analysis, and can comment on a draft, but must never write any part of it. The work must be entirely the student's own, and students should check their school's rules with their teacher before getting outside help.
Where to go next
The pages below cover IB tutoring and the feedback service.
