QCE Biology IA3 research investigation: how to get top marks

Your IA3 is worth 20% and is marked out of 20, five marks each across four criteria: Forming and Finding, Analysing, Interpreting, and Evaluating. You do not run an experiment. You evaluate a claim relevant to Unit 4 using secondary evidence you research yourself, and the marks reward how well you compare several credible sources against each other, not how many you list.

This guide describes the Biology 2025 syllabus (v1.3), which applies to Year 12 students from 2026. Advice mentioning a Communication criterion, or criteria called Research and planning, Analysis and interpretation, or Conclusion and evaluation, was written for the 2019 syllabus and those names no longer exist.

What the task actually asks

You evaluate a claim relevant to Unit 4, chosen from a list your teacher provides. The task is to research secondary evidence, not to collect your own data, and to reach a justified position on whether the evidence supports the claim.

Conditions. Individual task, roughly 10 hours of class time.

What can be done as a group: selecting the claim, identifying the relevant concepts, and conducting the research. Everything after that, the analysis and the write-up, is yours alone. If you and a classmate researched together but write near-identical interpretation or evaluation sections, that is a problem the individual-work requirement exists to catch.

Since Unit 4 now includes cladistics and phylogeny, claims can be drawn from that content as well as from genetics and heredity, or the continuity of life on Earth.

How it's marked: the criteria, and where students mix up IA2 and IA3

Both assessments are built from the same five inquiry stages, Forming, Finding, Analysing, Interpreting and Evaluating, and both merge two of them to end up with four criteria worth 5 marks each. They merge at opposite ends of the sequence.

IA2 combines Interpreting and Evaluating and keeps Forming and Finding separate. IA3 does the reverse: it combines Forming and Finding, and marks Interpreting and Evaluating as two criteria.

That single sentence is the whole difference, and it repays a second read if you learned the IA2 structure first, because the instinct it gives you here is exactly backwards.

As with IA2, there is no standalone Communication criterion. Genre conventions and referencing are marked inside Forming and Finding.

Forming and Finding: top-band characteristics

QCAA's top-band descriptors for this criterion describe:

• a considered rationale showing clear development of the research question from the claim
• a specific and relevant research question
• selection of sufficient and relevant sources
• appropriate genre conventions
• acknowledgment of sources through referencing

The research question has to develop out of the claim, not restate it. If the claim is a one-line statement your teacher gave the class, your rationale needs to show the thinking that turns it into a question you can actually research and answer.

What counts as a credible source

The syllabus is more permissive than most students assume (p. 47). Credible sources include:

• books and podcasts by well-credentialed scientists
• "popular" science websites or magazines
• websites of governments, universities, independent research bodies, or science and technology manufacturers
• scientific journals

What earns top marks in Analysing, Interpreting and Evaluating

The subject report is specific about what separates strong responses from weak ones (pp. 31-32):

• Trends identified within and between sources. Not just what one source found, but what the same pattern looks like across several, using referenced snips of relevant tables and graphs, sequenced logically.
• Multiple sources. The more sources you use well, the more you can show that the limitations of one are addressed by another, and establish corroboration between them. A conclusion resting on one source cannot corroborate itself.
• Limitations specific to the research question. Not a generic list of weaknesses, but an explanation of how or why each limitation makes the evidence less effective for answering your particular question.
• Evidence quality discussed in terms of bias, currency, relevance and missing data, and how each of those affects how much weight the evidence should carry.
• Accurate terminology. The subject report specifically names gene versus allele as a confusion that costs students marks, and it recurs across multiple report years in Biology more broadly. If your claim touches genetics, know which word you mean before you write it.
• Full referencing. In-text referencing throughout, a consistent style (APA or Harvard, not a mix of both), and a complete bibliography.

Evaluating, where the marks actually move

Of the four IA3 criteria, Evaluating is the one schools and QCAA agree on least, in every one of the four cohorts on record. It is the criterion to spend your last hours on.

It carries three things: a justified discussion of the quality of your evidence, extrapolation of credible findings from your research to the claim, and suggested improvements and extensions. Two of those run on ladders you should know exactly.

Evidence quality runs justified at the top, then reasonable, then cursory or simplistic. A discussion becomes justified when it says how a factor changes the weight the evidence should carry, not merely that the factor exists.

Findings run extrapolation of credible findings at the top, then application of relevant findings, then application of insufficient or inappropriate findings. The top band is doing something specific: taking what your sources established and carrying it to the claim, while saying where that carry stops.

The drafting rule

You get one almost-complete draft. This comes directly from the QCE handbook (section 8.2.5). Learn it now, not when you ask for a second round of feedback and cannot get one. Plan your ten hours of class time so that draft happens once, close to finished, not as an early rough cut you expect to revise repeatedly with your teacher.

Common mistakes

Relying on a single strong source instead of several. One good source cannot show corroboration. The report specifically rewards trends found across multiple sources, so a thorough investigation of three or four sources will usually score better than an exhaustive treatment of one.

Writing limitations as a generic list. "This source might be biased" is not a limitation until you say how or why that bias affects the evidence for your specific question. Tie every limitation back to your research question.

Assuming only journal articles are credible. See the credible sources list above. Ruling out government, university and well-credentialed popular science sources narrows your evidence base for no reason the syllabus requires.

Mixing up the IA2 and IA3 criterion structure. IA3 combines Forming and Finding but keeps Interpreting and Evaluating separate. Check which task you are writing for before you plan your response against a remembered criteria list.

Confusing gene and allele. Named explicitly in QCAA's commentary. Check every instance before submitting if your claim touches genetics.

Doing analysis or write-up as a group. Selecting the claim, identifying concepts and researching can be shared. Writing near-identical interpretation or evaluation with a classmate undermines the individual-work requirement.

Inconsistent referencing. Pick APA or Harvard and use it throughout, with in-text citations and a complete bibliography. A mixed or incomplete reference list is graded inside Forming and Finding, so it costs marks even though it looks like a formatting issue.

Assuming a second draft is coming. It is not. See the drafting rule above.

Weak versus strong wording

These pairs are drawn from student work QCAA reproduced and annotated in its subject reports, so the right-hand column is what a real top-band response actually did.

Before you submit

• Does your research question develop clearly from the claim you were given?
• Have you used multiple credible sources, not just one, however strong?
• Does every limitation you raise explain how or why it affects evidence for your specific question, instead of restating a generic weakness?
• Have you discussed evidence quality in terms of bias, currency, relevance and missing data?
• Have you checked every use of "gene" and "allele" if your claim touches genetics?
• Is your referencing consistent, in APA or Harvard, with in-text citations and a complete bibliography?
• Did you treat your one draft as close to final, not as a rough first attempt?

See the IA1 data test guide and the IA2 student experiment guide for the other two internal assessments, or head back to the QCE Biology subject page for the full picture of how Biology is assessed.