The IA (Internal Assessment) is one of the many things IB students struggle with, but some might feel that writing the IA in Physics is especially confusing since it involves experiments and calculations. This post is for those who are having a hard time coming up with a topic, are worried about writing the IA in Physics overall, or are interested in Physics but not so sure about taking it because of the IA.
An overview of IB Physics can also be seen in a previous post: Exam Strategy for IB Physics (HL/SL).


1. Overview of Physics IA

Physics IA is worth 20% of the final grade for the subject at both HL/SL levels. According to the official subject brief published by IBO, Physics IA is an “open-ended task in which the student gathers and analyses data in order to answer their own formulated research question”. There is no word limit in the written report but it should be 6-12 pages long. However, from the final assessment of 2025 (for IB students with new Physics curriculum from August 2023), the written report will have a word limit of 3,000 words.

Let’s take a look at the criteria for Physics IA to catch up on the key factors you need to consider when writing your IA.

Criteria Components Assigned Points / Weightings Expected Characteristics
Personal Engagement 2 points / 8%

The evidence of personal engagement with the exploration is clear with significant independent thinking, initiative or creativity.

The justification given for choosing the research question and/or the topic under investigation demonstrates personal significance, interest or curiosity.

There is evidence of personal input and initiative in the designing, implementation or presentation of the investigation.

Exploration 6 points / 25%

The topic of the investigation is identified and a relevant and the fully focused research question is clearly described.

The background information provided for the investigation is entirely appropriate and relevant and enhances the understanding of the context of the investigation.

The methodology of the investigation is highly appropriate to address the research question because it takes into consideration all, or nearly all, of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.

The report shows evidence of full awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation.

Analysis 6 points / 25%

The report includes sufficient relevant quantitative and qualitative raw data that could support a detailed and valid conclusion to the research question.

Appropriate and sufficient data processing is carried out with the accuracy required to enable a conclusion to the research question to be drawn that is fully consistent with the experimental data.

The report shows evidence of full and appropriate consideration of the impact of measurement uncertainty on the analysis.

The processed data is correctly interpreted so that a completely valid and detailed conclusion to the research question can be deduced.

Evaluation 6 points / 25%

A detailed conclusion is described and justified which is entirely relevant to the research question and fully supported by the data presented.

A conclusion is correctly described and justified through relevant comparison to the accepted scientific context.

Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are discussed and provide evidence of a clear understanding of the methodological issues involved in establishing the conclusion.

The student has discussed realistic and relevant suggestions for the improvement and extension of the investigation.

Communication 4 points / 17%

The presentation of the investigation is clear. Any errors do not hamper the understanding of the focus, process and outcomes.

The report is well structured and clear: the necessary information on focus, process and outcomes is present and presented in a coherent way.

The report is relevant and concise thereby facilitating a ready understanding of the focus, process and outcomes of the investigation.

The use of subject-specific terminology and conventions is appropriate and correct. Any errors do not hamper understanding.

Total 24 points / 100%



2. Examples of Physics IA Topics

Many IB graduates have kindly answered an online survey by MakeSensei and given examples of IA topics they chose in IB Physics.

2.1 SL

  • Investigating the relationship between the area of a damper and the decay constant of oscillating mass.
  • Investigating the efficiency of portable wind turbine generators
  • Investigating the effects of changing the length of a thermal couple
  • Effect of varying pressure values on a football’s coefficient of restitution.


2.2 HL

  • How does the angle of incline affect the final velocity of a ball dropped from the top of the incline with constant displacement?
  • Investigating the relationship between drop height and the sound intensity of a ball



3. Tips for Physics IA

3.1 Choose Appropriate Methods

There are many options for how to carry out your investigation. But without choosing the right ones, it would be time-costly, meaning inefficient, because you can’t find useful data from the wrong sources. So, it’s best to make a clear plan beforehand, of which sources you’re getting data from, whether it’s a lab experiment, a simulation, or secondary sources like previous academic studies. You can also talk to your teacher for better methods because after all, they are the ones who will mark your IA.


3.2 Have a Clear Structure

Just like many other IAs, Physics IA should also have a clear structure to make it easier for readers to follow your scientific investigation. If you’re aiming for a score of 6/7, following components can help you organize the written report as headings.

  1. Aim / Research Question(s)
  2. Introduction
  3. Variables
  4. Apparatus
  5. Method
  6. Raw Data
  7. Processed Data
  8. Conclusion
  9. Evaluation
  10. References


3.3 Don’t Be Afraid to Use Diagrams

When you’re trying to explain something to someone else, the most important thing is that your explanation is clear and simple. But when you’re stuck, diagrams and figures are often very helpful. Having suitable diagrams for your data not only helps readers understand your investigation process, but also shows them you know enough to choose the most effective way to present in limited pages/words.



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