Unit Synthesis and Depth Study Preparation
In 2022, a Year 9 student at CSIRO's STEM Academy won a national science award with a 3-week depth study on rust rates — all starting from 1 well-chosen question about everyday change.
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● Know
- A depth study is an extended investigation into a question of your choice.
- This unit covered change in matter from many angles: classification, evidence, modelling, conservation, real-world applications.
- A good depth study question is specific, testable and safe.
● Understand
- Depth studies combine everything you've learned about variables, evidence, modelling and safety into one project.
- Planning is most of the work — the experiment itself is short.
- The quality of method matters more than how interesting the results are.
● Can do
- Choose a depth study question linked to change in matter.
- Write a plan including IV, DV, CVs and a risk assessment.
- Identify the key risks and the safety steps that control them.
Imagine placing 3 identical iron nails in 3 different conditions: one submerged in salt water, one submerged in fresh water, and one left in dry air — then returning after 2 weeks to measure the orange rust coating on each. That simple setup answers a precise, testable question: "Does water type affect the rate of rusting?" That is exactly the shape of a good depth study. A depth study is an extended investigation that you design and carry out yourself. The quality of your study depends almost entirely on the question you choose. A good question is specific, testable, and safe.
Specific means narrow enough to investigate in the time available. “How does temperature affect how fast salt dissolves in water?” is specific. “How does chemistry work?” is not. Testable means you can change one variable, measure another, and collect data with school equipment. Safe means no dangerous chemicals, no risky procedures, and no equipment you cannot access. Your teacher is there to help you refine your question before you begin.
“How does the surface area of a tablet affect the rate of reaction with acid?” This question names the IV (surface area), the DV (reaction rate), and implies the need for controlled variables such as acid concentration and temperature. It can be tested safely with a stopwatch and a ruler.
CSIRO scientists designing field experiments follow the same criteria. A recent study on microplastic filtration asked, “Which mesh size removes the most microplastics from storm water?” — specific, testable, and safe — and produced actionable results for local councils.
Students often think a broad question sounds more impressive. In science, breadth kills depth. A narrow question lets you control variables, collect precise data, and draw a strong conclusion.
Before you pick up a single piece of equipment, write a complete plan. Your plan should include the inquiry question, a hypothesis linking IV and DV, a list of controlled variables, a step-by-step method, a blank results table, and a risk assessment.
A detailed method must be so clear that another scientist could repeat your experiment without asking questions. List every piece of equipment and describe each step in order. Sketch your results table with column headers and units already filled in. This preparation saves time, prevents surprises, and shows your teacher that you understand the investigation before you start. Reviewers judge depth studies mainly on the quality of the method, so get this right and the data will tell its own story.
A student planning a reaction-rate experiment lists: 1) 50 mL beaker, 2) 0.5 mol/L hydrochloric acid, 3) magnesium ribbon (2 cm lengths), 4) stopwatch, 5) thermometer. Their method describes how they will measure time from when the magnesium enters the acid until bubbles stop.
At ANSTO, every experiment begins with a written protocol reviewed by a safety committee. The protocol includes equipment, steps, hazards, and emergency procedures — the same structure you use in a school depth study, just at a professional level.
Some students think planning is a waste of time and prefer to “just try it.” Unplanned experiments produce ambiguous data, missed controls, and results that cannot be interpreted. Good scientists plan obsessively.
A scientific report has a standard structure that lets others follow your thinking and repeat your work. The introduction sets the background and aim. The method describes exactly what you did. The results present raw data in tables and graphs. The discussion interprets the data, identifies limitations, and compares with other studies. The conclusion summarises the findings and links them back to the aim and hypothesis.
Each section has a distinct job. Mixing them up confuses the reader and weakens your argument. Think of the report as a story: introduce the characters, describe the action, show the evidence, explain what it means, and end with the moral.
In the discussion section, a student might write: “My results supported the hypothesis that surface area increases reaction rate. However, I only tested one acid concentration, so I cannot be sure the trend holds at other concentrations.” This shows scientific maturity.
CSIRO publishes peer-reviewed reports that follow this exact structure. Policymakers rely on clear methods and honest discussions of limitations when deciding how to allocate funding for research and environmental protection.
Students often write the conclusion as a list of everything they learned in the unit. A conclusion should only summarise what this specific investigation found and how it relates to the original hypothesis.
- Introduction
- Method
- Results
- Discussion
- Conclusion
- Summary of findings linked back to the aim and hypothesis
- Raw data presented in tables and graphs
- Interpretation, limitations, and comparison with other studies
- Step-by-step procedure for repeating the experiment
- Background and aim of the investigation
Depth studies fail for predictable reasons. The most common is a question that is too broad to investigate properly. Another is poor planning — starting practical work without a clear method or risk assessment. A third is changing data to fit the hypothesis, which is scientific misconduct and destroys trust in your results.
Other traps include introducing new evidence in the conclusion, ignoring safety and ethics until the last minute, and failing to evaluate limitations. The best defence is honesty and organisation. State what went wrong, suggest specific improvements, and never pretend an experiment was perfect when it was not. Evaluating limitations shows scientific maturity and strengthens your argument.
A student’s depth study asks, “How does temperature affect chemical reactions?” They test three reactions and conclude that temperature makes all reactions faster. This overgeneralises from three examples to every reaction in the universe. A better question would focus on one specific reaction.
The Australian Research Council requires every funded project to include a limitations statement and a plan for managing risks. This professional standard mirrors exactly what you are learning to do in your school depth study.
Some students think admitting limitations makes their work look weak. The opposite is true. Recognising what could have gone wrong shows that you understand the investigation deeply and know how to improve it next time.
Here's a student's working. One line has an error — click it.
- A student's depth study asks: 'How does temperature affect chemical reactions?'
- They test three reactions at room temperature, 40°C, and 80°C.
- In their conclusion, they write: 'Temperature affects all chemical reactions by making them faster, which proves my hypothesis correct.'
This unit has taken you from the particle model to the planet. You have learned that chemical change involves rearranging atoms, that energy drives reactions, and that variables must be controlled to find true cause and effect. You have seen these principles at work in nature, in industry, and in your own experiments.
A depth study is your chance to apply everything. Choose a question that matters to you, plan it carefully, collect honest data, and interpret it critically. The skills you practise now — forming hypotheses, controlling variables, and writing clear reports — are the same skills professional scientists use every day. Science is not a subject you finish; it is a way of thinking you keep refining.
A student might investigate how Indigenous fire-management practices affect soil pH compared with uncontrolled wildfire. The investigation links chemical change, ecological knowledge, and real-world management — exactly the kind of synthesis that makes science meaningful.
CSIRO’s Young Indigenous Women’s STEM Academy supports students conducting depth studies that combine traditional knowledge with modern science. These projects show that the best investigations often bridge cultures and disciplines.
Some students think a depth study is just a long essay. It is not. It is an investigation. You must design, carry out, and evaluate a real experiment, not just summarise what others have found.
At the start of this lesson, you considered whether you could explain the difference between synthesis and decomposition to someone who had missed the entire unit.
Now that you've synthesised everything, how confident do you feel? What's the one idea that feels completely locked in — and is there anything you'd still want to revisit before your depth study?
1. Which of the following best describes a depth study?
2. What is the purpose of evaluating limitations in a scientific report?
3. Which section of a scientific report presents the raw data?
4. What should you do if your data does not support your hypothesis?
5. Which of these is a good depth study question?