QCE Chemistry IA1 data test: how to get top marks

Your IA1 is worth 10% of Chemistry, marked out of 10 on a single criterion using a percentage cut-off, not performance bands. Every instrument QCAA approves splits its marks close to 30% on unknown quantities, 30% on trends and patterns, and 40% on conclusions drawn from analysis, so the shape of the paper is fixed before you sit it. The single biggest lever on your mark is Objective 4: stating a conclusion and the reasoning behind it, not just getting a number right.

This guide describes the Chemistry 2025 v1.0 General Senior Syllabus, current for Year 12 students from 2026. IA1's marking mechanism, the percentage cut-off ladder, is almost unchanged from the superseded Chemistry 2019 v1.3 rules, so the four subject reports published so far (2022 to 2025 cohorts, all assessed under 2019 v1.3) are safe to draw on for how that ladder actually gets applied in practice. Their criterion names and cohort statistics for IA2 and IA3 do not carry across the same way, because those instruments changed more.

What the task actually asks

IA1 is a supervised, individual data test sat in one sitting: 5 minutes perusal and 60 minutes working time, with a QCAA-approved graphics or scientific calculator. You are given between two and four datasets you have not seen before, drawn from Unit 3 practicals, activities or case studies (chemical equilibrium systems and oxidation and reduction). Responses are single words, calculations, or sentences up to 150 words per question.

Only three of the six assessment objectives are examined here: apply (Objective 2), analyse (Objective 3) and interpret (Objective 4). Objectives 1, 5 and 6, describe, evaluate and investigate, sit outside IA1 entirely.

The question specifications table

QCAA requires every IA1 instrument your school writes to match these proportions within ±2%:

This is the single most useful thing published about IA1, because it tells you the shape of a paper you have not sat. Two things follow. Conclusions carry the largest block of marks, at around 40%, a different skill from calculation and the one most students under-practise. And the verb in front of you names the objective: work out which row of the table a question sits in before you start writing, and you know what the marker is looking for.

The 2025 table moved one verb across the boundary. Under the 2019 syllabus, compare sat in the conclusions row; QCAA's own note explains the change, that "the cognitive verb compare now aligns more closely to Assessment objective 3 (Analyse data) as it relates to the similarities and differences." Distinguish dropped out of objective 3 in the same revision, and determine, draw (a conclusion) and interpolate are new to objective 4.

How marks are awarded

IA1 has one criterion, Data test, worth 10 marks across objectives 2, 3 and 4. It is not marked against a five-band descriptor table the way IA2 and IA3 are. QCAA converts your raw score to a percentage and reads it off a cut-off ladder:

>90% = 10 · >80% = 9 · >70% = 8 · >60% = 7 · >50% = 6 · >40% = 5 · >30% = 4 · >20% = 3 · >10% = 2 · >1% = 1 · ≤1% = 0

Compare that against a response that clears the line: QCAA's 2024 report gives "13/20 is 65%, which is > 60%, therefore a mark of 7." One extra correct mark, landing on the right side of a threshold, is worth a full step up the ladder.

Every mark band is a 10-percentage-point step, and there is no descriptor to reach by writing more elaborately. Picking up individual marks across the whole paper, not polishing any one answer, is the only lever IA1 gives you.

How reliably IA1 gets marked

Of the three internal assessments, IA1 is the one your school is most likely to mark exactly as QCAA would, once it is approved. Confirmation agreement on the single Data test criterion has run 99.27% (2022), 98.29% (2023), 100.00% (2024) and 100.00% (2025). Endorsement, when your school submits the instrument for approval before anyone sits it, tells a different story: 41% (2022), 39% (2023), 61% (2024) and back down to 41% (2025), mostly failing on how well the instrument aligns to the specifications table above.

Both figures describe your teacher's instrument design and marking, not your own performance, but they point to something useful: once your data test is approved and sat, the mark you're given is very likely the mark you keep. IA2 and IA3 move at confirmation far more often. The Chemistry study guide covers that pattern across all three assessments.

Common mistakes

Answering from theory instead of the dataset. Objective 3 and 4 questions must be answered from evidence in the data you were given. QCAA's 2023 report states the rule directly: these questions "must relate to the evidence in the data provided, not the methods of data collection or knowledge of the experimental method." Its 2025 report gives a concrete example, warning schools against a question students could answer using theory related to Le Chatelier's principle without ever reading the dataset. If you can answer a question from memory alone, check again: it is almost certainly asking you to read a number, a trend or a pattern off the stimulus instead.

Getting chemical formula conventions wrong. Subscript conventions in chemical formulas are flagged in the 2023, 2024 and 2025 reports as a mistake that costs marks in exactly this instrument. The safest habit under time pressure is writing every formula exactly as it would appear in the syllabus, subscripts included, instead of reconstructing it from memory.

Giving only half of a two-part answer. QCAA's 2025 report describes a titration item worth two marks: one for correctly classifying the acid as weak or strong, and one for "an appropriate justification based on evidence, such as a description of the initial pH, the identification of a buffer zone, and a description of the vertical region of the graph at equivalence." A classification with nothing behind it, or a description with no stated classification, only ever earns one of the two.

Weak versus strong responses

QCAA reproduces marked IA1 excerpts in its subject reports with the mark each one earned. The pattern across them is the same every year: the strong response turns a qualitative claim into a specific number or feature taken from the dataset.

Where our data lines up with the specifications table

QCAA names the cognitive verb as the thing that decides a response every year, but it does not publish a score per verb. Our own marking data does, and it lines up with the specifications table above. Across 34,620 marked attempts on 736 Chemistry questions on AusGrader, the two objective-4 verbs behind the conclusions row are also our weakest overall: deduce averages 52.4% (n=67) and justify 52.4% (n=149). The objective-2 verbs sit in the middle of our table, calculate at 62.9% (n=392) and determine at 59.4% (n=434), and identify, which appears in both the objective-2 and objective-3 lists, is our second-strongest verb at 83.9% (n=1,917). The full ranking across all the verbs we measure is on the Chemistry study guide.

That pattern runs backwards from the mark weighting: the objective carrying the most marks, conclusions at around 40%, is built from our weakest verbs, and the objective students find easiest, identifying a value or feature, carries the least.

In the room

There's no draft to check, since IA1 is sat under supervision, so treat this as a routine to run on every question as you reach it:

• Which row of the specifications table does the verb belong to: unknown quantities, trends and patterns, or a conclusion?
• How many marks is the question worth, and how many separate points does that mean the answer needs?
• If you're asked for a conclusion, have you written the conclusion itself and the reasoning that supports it, not just one of the two?
• Does your answer use a specific value from the dataset in front of you, not general chemistry theory?
• On a calculation, is every step shown, with correct subscripts and units carried through?

Ready to practise? Work through unseen QCE Chemistry datasets on the Chemistry question bank, see how IA1 fits into the rest of the subject on the QCE Chemistry study guide, or read how the IA2 student experiment and IA3 research investigation are marked, both built around a very different set of QCAA adjectives from anything IA1 asks of you.