QCE Physics IA2 student experiment: how to get top marks

QCE Physics IA2 is worth 20% of your final result and is marked out of 20, five marks across four criteria: Forming, Finding, Analysing, and Interpreting and Evaluating. In every one of them, the gap between the middle band and the top band comes down to one or two words: considered instead of reasonable, justified instead of feasible, thorough instead of obvious. Knowing exactly what QCAA means by those words is most of the task. This guide works through each criterion using QCAA's own definitions and real marked examples from four years of subject reports.

This guide describes the Physics 2025 syllabus (v1.2), which applies to Year 12 students from 2026. If you're reading advice that mentions a Communication criterion, or criteria called Research and planning or Analysis of evidence, it was written for the superseded 2019 syllabus. No subject report yet describes assessment under the current criteria; the first is expected around January 2027. That applies to every marked example below: however recent the report it comes from, it was written and scored under the 2019 criteria, so read them for technique and not as a picture of what a 2025 top band looks like.

What the task actually asks

You're modifying an experiment, not building one from scratch. The syllabus asks you to refine, extend or redirect an experiment relevant to Unit 3, drawn from a practical or simulation you've already done in class, to address your own related research question. Unit 3 splits into gravity and motion and electromagnetism, so your modified experiment has to sit inside one of those.

The task takes you through identifying an experiment to modify, developing a research question, conducting a risk assessment, running the experiment, collecting data, processing and analysing it, interpreting your results, evaluating reliability and validity, and suggesting improvements and extensions. QCAA designs it to take around 10 hours of class time.

Conditions. Written up to 2000 words, or multimodal up to 11 minutes with at least two modes delivered at the same time.

What can be done as a group: identifying an experiment, developing the research question, conducting the risk assessment, running the experiment, and collecting data. Everything from there, processing, analysing, interpreting, evaluating and writing up, is yours alone.

Forming (5 marks)

Marked on your rationale, your modifications to the original experiment, your research question, whether your method collects enough of the right data, and your use of genre and referencing conventions.

QCAA's top band asks for: a considered rationale; justified modifications to the methodology; a specific and relevant research question; a methodology enabling collection of sufficient and relevant data; and appropriate use of genre and referencing conventions.

A considered rationale, in QCAA's own words, demonstrates how your research question was developed, giving consideration to how the dependent, independent and control variables relate to the topic of investigation. The 2022 report adds two more expectations: document the development of the research question from the original experiment, and link the research question back to the justification for your modifications.

A specific research question explicitly states the relationship between an independent and dependent variable and is directly related to the data you'll collect. A relevant one links appropriate subject matter to the experiment you're running.

The rationale carries a separate requirement, and QCAA marks them separately: a relevant rationale has to name equations correct for the context. The 2024 report is direct about the failure mode, that Coulomb's law does not relate to an experiment using bar magnets. Getting the research question right does not cover you here.

Genre and referencing conventions are marked in this criterion too. The 2024 report names appropriate headings and captions, a formal tone and past tense, with consistent referencing in APA or Harvard.

Justified modifications go further than description. QCAA states the failure mode plainly: collecting more data using an unmodified experimental method is not sufficient. Each modification needs its own sentence explaining how it improves reliability, validity, or both.

Finding (5 marks)

Marked on your management of risks, ethical and environmental issues, the raw data you collect, and your scientific language.

Top band: considered management of risks, ethical and environmental issues; collection of sufficient and relevant raw data; and fluent and concise use of scientific language and representations.

Considered management, in near-identical wording across three reports, means the impacts of risks and their management are considered with respect to how the methodology is actually carried out. A generic hazard table does not meet that bar.

Fluent and concise use of scientific language means symbols, units and prefixes appropriate for the context (SI units, such as kg for mass), indicators of measurement uncertainty such as significant figures, and graphs with lines of best fit that demonstrate trends. The 2024 report adds scatter graphs with a linearised line of best fit where possible. Genre conventions and referencing are marked under Forming, not here.

Analysing (5 marks)

Marked on how you process your data and what you find in it.

Top band: correct and relevant processing of data; thorough identification of relevant trends, patterns and relationships; and thorough and appropriate identification of the uncertainty and limitations of evidence.

A thorough identification of trends should be linearised, where appropriate, and linked to a relevant physics formula. QCAA's 2025 wording is that it should accurately describe the processed data and lead to a valid conclusion.

Uncertainty work is where the bands separate most clearly. Thorough and appropriate identification means correct calculations that account for measurement error, consideration of error bars on graphs, and maximum and minimum trendlines. The 2023 report adds linearisation of data including correlation coefficients (r²). The two formulas the syllabus itself gives for this are absolute uncertainty, $\Delta \bar{x} = \pm \dfrac{x_{max} - x_{min}}{2}$, and percentage uncertainty, $\text{percentage uncertainty (\%)} = \dfrac{\text{absolute uncertainty}}{\text{measurement}} \times 100\%$.

Interpreting and Evaluating (5 marks)

Marked on your conclusion, your discussion of reliability and validity, and your improvements and extensions.

Top band: justified conclusion(s) linked to the research question; justified discussion of the reliability and validity of the experimental process; and suggested improvements and extensions logically derived from the analysis of evidence.

A justified conclusion, in near-identical wording across three reports, refers to the trends, patterns or relationships identified in your analysis to show how the evidence matched the theoretical concepts named in your rationale. A justified discussion of validity is made with reference to the accepted and constant values derived from the relevant equation in your rationale, so if your rationale never named the governing equation, you have nothing to check validity against.

What QCAA's checks show about IA2

QCAA checks your school's IA2 task before you sit it, called endorsement, and checks the marking afterwards, called confirmation. IA2 endorsement at the first review stage ran 83%, 90%, 92% and 88% across the 2022 to 2025 cohorts. The number of additional samples QCAA had to request after confirmation fell sharply after 2022, from 90 down to zero, then 3 and 3 in the three years since. The reports don't explain the drop, so read it as a one-off rather than a trend.

How your mark compares once QCAA checks it, confirmation agreement, is tracked across all three internal assessments on the QCE Physics study guide.

Common mistakes

Collecting more data with an unmodified method. QCAA states plainly that this does not count as a justified modification. Every change needs its own sentence saying how it improves reliability or validity.

Identifying a trend without linking it to a physics formula. A thorough identification of trends is one that is linearised, where appropriate, and tied back to the formula that governs it, not just described in words.

Discussing reliability in general terms. "The experiment was reliable" says nothing on its own. The top band wants the discussion tied to specific aspects of your design or data collection, referenced against the values in your rationale.

Putting method problems in Analysing. Uncertainty and limitations there have to come from your data. Save the critique of your procedure for Interpreting and Evaluating.

Generic risk assessments. If your hazard table would fit any experiment in the school, it is not considered management. Tie every risk to your actual apparatus and how you actually ran the method.

Looking for a Communication mark. It no longer exists as its own criterion. Genre, referencing and scientific language are marked inside Forming and Finding now, so weak referencing costs marks in a criterion worth 5, not 2.

Weak versus strong wording

Before you submit

• Does your rationale explain why your independent and dependent variables are the relevant ones, and name the equation that actually governs your experiment?
• Does every modification say how it improves reliability, validity, or both?
• Have you avoided collecting extra data with an unmodified method and calling it a modification?
• Is every risk in your risk assessment specific to your actual apparatus and method?
• Do your trend statements link back to a relevant physics formula?
• Have you calculated percentage uncertainty and shown the working, not just stated a number?
• Are your limitations in Analysing about your data, with the evaluation of your process saved for Interpreting and Evaluating?
• Does every improvement trace to a reliability finding, and every extension to a validity limit, both logically derived from your analysis?
• Is your referencing consistent throughout, in APA or Harvard?