IB Physics IA Criteria Explained (2025) - Checklist for Scoring Top Marks

What is the IB Physics IA?

The IB Physics IA is a student-designed investigation that counts for 20% of your final grade. You choose the question, carry out the experiment, and present your findings in a structured report.

This guide breaks down exactly what examiners are looking for - based on the official rubric and what’s worked for the thousands of students we’ve supported over the past decade.

If you understand the four assessment criteria and plan your work around them, you’ll avoid the most common mistakes and give yourself the best chance at a top score.


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IB Physics IA Criteria: Quick Overview

Your Physics IA is marked out of 24 points, split evenly across four criteria:

  • Criterion A: Research Design – How clearly you define your research question and method

  • Criterion B: Data Analysis – How well you process, present, and interpret your data

  • Criterion C: Conclusion – Whether your findings answer the question and show understanding of the physics

  • Criterion D: Evaluation – How thoughtfully you reflect on the strengths, limitations, and improvements

Each criterion is worth 6 marks, and examiners follow the same rubric for both SL and HL students. The only difference is that HL students often take on slightly more complex topics — but the expectations for structure, clarity, and scientific reasoning are identical.


IB Physics IA Criterion A: Research Design

What does a strong research design look like in your IB Physics IA?

This first criterion is about how well you’ve planned your investigation. It covers your research question, experimental method, and whether your design shows you understand the physics behind what you're doing.

What Examiners Look For:

  • A clear, focused, and testable research question

  • A method that’s detailed and logical — someone else should be able to follow it and get similar results

  • Well-defined independent, dependent, and controlled variables

  • Justified decisions — not just what you did, but why you did it that way

  • Attention to safety, ethics, or environmental concerns (if relevant)

What to Include for Physics IA Research Design: 

  1. Your research question, stated clearly

  2. A brief explanation of your setup and the reasoning behind it

  3. A table or list of variables, with how you’ll control or measure them

  4. Any safety precautions, ethical considerations, or disposal methods

Good vs. Weak Design:

Strong Research Design Weak Research Design
“How does increasing the length of a pendulum affect its period?” “Pendulum experiment”
Variables are clearly defined and controlled No defined variables or unclear method
Method is step-by-step and justifies each choice No explanation of choices or how results will be measured
Safety noted (e.g., securing the stand) Missing safety or ethical considerations
 

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IB Physics IA Criterion B: Data Analysis

How should you collect, process, and present data in your Physics IA?

This criterion focuses on how well you collect, organize, and analyze your data — and whether your processing shows a clear understanding of what your results actually mean.

What Examiners Look For:

  • Relevant and sufficient data – enough points to see a trend, with repeated trials and a good variable range

  • Clarity and structure – clean tables and graphs with correct units, labels, and significant figures

  • Uncertainty and error treatment – uncertainties shown in measurements and carried through calculations; error bars where appropriate

  • Consistent processing – correct calculations, sample workings shown, and logical flow from raw data to findings

  • Interpretation of results – clear identification of trends or relationships, and any anomalies or inconsistencies noted

What to Include in the Physics IA Data Analysis:

  1. Raw data tables with headings, units, and uncertainty values

  2. Graphs that visualize trends - fully labeled, with titles, error bars, and best-fit lines if needed

  3. At least one worked example of a key calculation

  4. Any commentary on data quality, reliability, and visible outliers

  5. A short explanation of what the data shows - not a full conclusion, but a bridge toward it

Good vs. Weak Analysis:

Strong Data Analysis Weak Data Analysis
Multiple trials, good range Too few data points to support a conclusion
Tables and graphs labeled, clean, and consistent Missing units, inconsistent formatting
Sample calculations with correct units and sig figs No working shown or incorrect math
Uncertainties clearly handled throughout Uncertainty ignored or only mentioned briefly
Trends explained and anomalies acknowledged Data listed but not interpreted
 

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IB Physics IA Criterion C: Conclusion

How do you write a strong, data-driven conclusion in your Physics IA?

This criterion is about how clearly and accurately you answer your research question — using your data, not just your intuition. A strong conclusion shows that you understand what your results mean and how they connect to the physics behind your experiment.

What Examiners Look For:

  • A clear, focused conclusion that directly addresses the research question

  • Evidence-based reasoning, with specific data or trends used to support your answer

  • Connection to physics theory — explain the results using concepts from the syllabus or literature

  • Acknowledgement of uncertainty — how reliable are your findings, and what limits your confidence?

What to Include in the Physics IA Conclusion:

  1. A direct answer to your research question

  2. Reference to key data values, trends, or graph results

  3. A short explanation linking your findings to relevant physics principles

  4. Brief mention of limitations or uncertainties that affect how confident you can be

Strong vs. Weak Physics IA Conclusions:

Strong Conclusion Weak Conclusion
“The results show a clear inverse relationship between resistance and temperature, consistent with theory.” “The experiment worked okay and shows something interesting.”
Cites specific data and trend lines from the graph Makes a general statement with no numbers
Links to physics (e.g. Ohm’s law, kinetic theory) No mention of relevant scientific concepts
Comments on uncertainty and reliability Ignores limitations or confidence level
 

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IB Physics IA Criterion D: Evaluation

What makes a good evaluation in the IB Physics IA?

This final criterion is about showing that you understand the strengths and limitations of your investigation — and how you’d improve it. 

What Examiners Look For:

  • Specific strengths and weaknesses in your design or execution

  • Identifiable sources of error — not just “human error,” but measurable limitations

  • Discussion of impact — how each issue may have affected your results or conclusion

  • Realistic improvements that directly address the limitations

  • Extensions or follow-up questions, if relevant

What to Include for the Physics IA Evaluation criteria:

  1. At least one clear strength and one clear weakness

  2. A short discussion of how the weakness may have influenced your findings

  3. Concrete suggestions — not just “use better equipment,” but what and why

  4. (Optional) A way the experiment could be expanded or adapted in future

Strong vs. Weak Evaluations:

Strong Evaluation Weak Evaluation
“Using a photogate reduced timing error — but friction in the pulley may have slowed the cart slightly.” “There may have been some human error or other random problems.”
Links each limitation to its effect on the data Lists flaws without explaining impact
Suggests realistic, relevant improvements Vague fixes like “do it more carefully”
Optional extension logically builds on the original experiment Off-topic or overly complex suggestions
 

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SL vs HL IB Physics IA: Is There a Difference?

The IA criteria are exactly the same for Standard Level and Higher Level Physics. Both are marked out of 24 using the same rubric — same structure, same expectations for clarity, analysis, and scientific thinking.

The only difference is in the typical complexity of the topic

  • HL Physics students often explore questions that involve more advanced theory or analysis.

  • SL Physics students can score just as highly with a well-designed investigation that hits all four criteria.

What matters most is how clearly you define your research question, carry out the experiment, and explain your findings — not how complicated the topic is.

 

Final Checklist: Use the Criteria to Review Your IA

Before you submit your Physics IA, run through this quick checklist to make sure you’ve covered what examiners are actually looking for:

  1. Is my research question focused — and is my method clearly explained and justified?

  2. Is my data relevant, well-organized, and processed with uncertainties?

  3. Does my conclusion directly answer the research question and link to physics theory?

  4. Did I evaluate the strengths and limitations honestly, with realistic improvements?

If you can say yes to all four, your IA is likely in strong shape.


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Need Help With Your IB Physics IA?

Whether you're still figuring out your research question or putting the final touches on your evaluation, you don’t have to do it alone.

Our IB Physics tutors offer targeted one-on-one support to help you:

  • Plan and refine your experiment

  • Strengthen your analysis and conclusions

  • Review your full draft before submission

Get expert feedback from tutors who’ve helped hundreds of students finish strong 

— and score high.

 
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