In QCE Physics, your three internal assessments (the data test, the student experiment and the research investigation) make up 50% of your final result. Physics students scored very highly on their internal assessments in 2025, so the details in QCAA's subject report can make the difference at the top end.
This guide breaks down the internal assessment sections of QCAA's 2025 Physics subject report. It covers how students scored on each IA, what strong responses did, and the changes under the revised 2025 syllabus that students completing Units 3 and 4 from 2026 need to know. For the external exam, see our companion 2025 QCE Physics external assessment breakdown.
Key Takeaways
- Internal assessments are worth 50% of your Physics result: data test (IA1) 10%, student experiment (IA2) 20%, research investigation (IA3) 20%.
- Results were very high: 50/50 was the single most common IA total, and about 31% of students got full marks on each of the experiment and research investigation.
- QCAA agreed with schools' marks 100% of the time for the data test, 88.65% for the experiment and 92.75% for the research investigation.
- Strong experiments quantified uncertainty properly, for example with maximum and minimum trendlines to find the uncertainty in a gradient.
- Strong research investigations broke the claim into parts, used calculations from credible sources and judged evidence on credibility, bias, relevance, accuracy and recency.
How Internal Assessment Works in QCE Physics
| Assessment | Type | Weighting | What You Do |
|---|---|---|---|
| IA1 | Data test | 10% | Answer short-response questions on datasets in a 60-minute supervised test |
| IA2 | Student experiment | 20% | Modify a Unit 3 practical, collect primary data, analyse it and write a scientific report |
| IA3 | Research investigation | 20% | Evaluate a claim about Unit 4 physics using secondary evidence |
| External assessment | Two examination papers | 50% | Units 3 and 4 |
Your school writes each IA, but before students sit it the QCAA must endorse it, checking that it matches the syllabus and is fair. After marking, the QCAA confirms a sample of student responses to check that your school's marks are accurate.
💡 New to the system? Read our explainer on how QCE internal assessments work.
How Students Scored in 2025
| Assessment | Maximum Mark | Approx. % on Full Marks |
|---|---|---|
| IA1 (data test) | 10 | 35% |
| IA2 (student experiment) | 20 | 31% |
| IA3 (research investigation) | 20 | 31% |
| Total IA | 50 | 15% |
Approximate values read from the mark distribution charts in QCAA's 2025 Physics subject report.
Full marks was the most common result on every IA, and most students finished in the 40s out of 50. In a cohort this strong, a single lost mark in the experiment or research investigation can move you noticeably down the field.
How Reliable Were School Marks?
| Assessment | Instruments Endorsed First Time | Samples Reviewed | Agreement With School Marks |
|---|---|---|---|
| IA1 | 48% | 2,844 | 100% |
| IA2 | 88% | 2,842 (+3 additional) | 88.65% |
| IA3 | 59% | 2,833 | 92.75% |
Source: QCAA Physics subject report, 2025 cohort.
What this means for students:
- Your data test mark will stand. QCAA agreed with every school's IA1 marks.
- About 1 in 9 schools' experiment marks were changed, mostly downwards. Research and planning was lowered most often (4.59% of samples), followed by Analysis of evidence (3.86%).
- Research investigation marks were rarely changed. The biggest adjustment was to Research and planning (3.14% lowered).
- Only 48% of school data tests were endorsed first time, mainly because questions did not align with the syllabus objectives.
IA1: Data Test (10%)
The data test is a 60-minute supervised test with questions on datasets, ideally from realistic experiments with graphed results.
What QCAA's Samples Show
- Back up relationships with data. A full-mark response identified an inverse square relationship between separation distance and force, then proved it with two data pairs: doubling the distance from 2 m to 4 m quartered the force (4.17 µN to 1.04 µN), as did doubling from 3 m to 6 m.
- Read values from the trendline. Another response took a point on the trendline (r = 0.40 m, v = 1.40 m/s), substituted into v = 2πr/T and found a period of 1.8 s.
- Cut-offs are applied exactly. 16/20 is 80%, which is not greater than 80%, so it earns 8, not 9.
- Marking schemes can accept a range for values read from graphs, such as a gradient between 3.5 and 4.1.
What Changes for IA1 Under the 2025 Syllabus
- Perusal time is 5 minutes.
- The question specifications have been revised. For example, compare now aligns more closely with analysing data (similarities and differences).
IA2: Student Experiment (20%)
The student experiment asks you to modify a Unit 3 practical, collect primary data, analyse it and write a scientific report that answers your research question.
How Students Scored on Each Criterion
| Criterion | Marks | Approx. % on Full Marks |
|---|---|---|
| Research and planning | 6 | 51% |
| Analysis of evidence | 6 | 51% |
| Interpretation and evaluation | 6 | 42% |
| Communication | 2 | 88% |
Approximate values read from QCAA's 2025 criterion charts.
What Earned the Marks
Research and planning: QCAA's sample research question named the variables and conditions exactly: "What is the relationship between angle of incline and acceleration produced by a car when it is released from the top of a ramp, with a constant mass and starting from rest, assuming friction and air resistance is negligible, and gravity is constant at 9.8 m/s²?"
The student justified every modification by saying whether it improved reliability or validity:
- trials increased from 2 to 3 to reduce the impact of outliers (reliability)
- the range increased from 4 angles to 6 (8° to 31°) to test the relationship more widely (validity)
- releasing the car instead of pulling it, to remove random error from an uneven pull (validity)
- a smart car that measures acceleration automatically, removing parallax error from reading a spring balance (reliability)
- rails so the car could not drift sideways (validity).
Analysis of evidence: Strong responses calculated and represented uncertainty properly. The ramp sample:
- plotted acceleration against sin θ with a line of best fit (R² ≈ 0.995)
- drew maximum and minimum trendlines to find the uncertainty in the gradient: (9.5735 − 8.9739) ÷ 2 = ±0.2998, or ±3.23%
- wrote the final relationship with its uncertainty: a = (9.27 ± 0.30) sin θ + (0.04 ± 0.10), which compares well with the theoretical a = g sin θ.
Interpretation and evaluation: Strong conclusions referred to the trends in the analysis and compared them with the theory in the rationale. Improvements were linked to reliability and the calculated uncertainties. Validity discussions referred to accepted values, such as comparing the gradient with g = 9.8 m/s².
Communication: Full marks needed correct symbols, SI units and prefixes, appropriate significant figures and graphs with lines of best fit.
What Changes for IA2 Under the 2025 Syllabus
- The task specification language now matches the mid-level descriptors in the marking guide.
- The criteria are organised differently (for example, Forming and Analysing), but the standards teachers apply are the same.
- A specific research question must state the relationship between the independent and dependent variables, and a considered rationale must explain how the dependent, independent and control variables relate to the topic.
IA3: Research Investigation (20%)
The research investigation asks you to evaluate a claim about Unit 4 physics (such as special relativity or quantum theory) using secondary evidence.
How Students Scored on Each Criterion
| Criterion | Marks | Approx. % on Full Marks |
|---|---|---|
| Research and planning | 6 | 60% |
| Analysis and interpretation | 6 | 47% |
| Conclusion and evaluation | 6 | 39% |
| Communication | 2 | 91% |
Approximate values read from QCAA's 2025 criterion charts.
What Earned the Marks
Research and planning: Strong rationales broke the claim into parts. One sample took the claim "The theory of special relativity has little, if any, effect in the ordinary, everyday world", explained time dilation and length contraction, then focused on GPS as an everyday technology affected by relativity. That led to a measurable research question: "Does GPS technology compensate for the impact of time dilation due to special relativity on its accuracy, and achieve aircraft positioning accuracy within 10 metres?"
QCAA also suggested claims that work well, such as "Black-body radiation paved the way for understanding energy quantisation" and "Light is better described as a wave than a particle".
Analysis and interpretation: Strong responses drew evidence from enough sources and used it in calculations. A GPS sample took the satellites' mean velocity (3,874 m/s) from a published table and calculated time dilation of about 7.2 µs per day without relativistic corrections.
Conclusion and evaluation: QCAA wants students to:
- judge the quality of evidence by checking the credibility, bias, relevance, accuracy and recency of each source
- list specific strengths and weaknesses, such as sources corroborating each other, or a model ignoring important variables
- extrapolate the findings to the claim, not just the research question. One sample found that uncorrected time dilation would cause positioning errors of about 2 km, then argued that all global navigation satellite systems depend on special relativity.
What Changes for IA3 Under the 2025 Syllabus
- The qualifiers describing each task specification have been revised.
- The syllabus now clarifies what counts as a credible, student-accessible source.
- Group elements have been added to some Forming and Finding activities.
💡 Get a clear picture of every cognitive verb with our complete guide to QCE cognitive verbs.
How to Improve Your Physics IA Results
- In the data test, support every relationship with data pairs and show substitutions.
- Write a research question that names every variable and condition.
- Justify each modification as improving reliability or validity.
- Use maximum and minimum trendlines to find the uncertainty in your gradient, and write your final relationship with its uncertainty.
- Compare your results with accepted values, such as g = 9.8 m/s².
- In the research investigation, break the claim into parts and choose a measurable research question.
- Use your sources' data in calculations, not just quotes.
- Evaluate every source for credibility, bias, relevance, accuracy and recency, then extrapolate to the claim.
For more preparation:
- read our 2025 QCE Physics external assessment breakdown
- follow our guide to getting an A in QCE Physics
- see our 2025 QCE Chemistry internal assessment breakdown
- learn how IA1, IA2 and IA3 work.
Need Help With QCE Physics?
Our QCE Physics tutors work one-on-one with students to prepare for the data test, design and analyse a high-scoring student experiment, and write a well-evaluated research investigation.
Source: Queensland Curriculum & Assessment Authority, Physics subject report, 2025 cohort (January 2026).
