Investigable questions, hypotheses and predictions — AC9S9I01

• Identify independent, dependent and controlled variables.
• Rewrite broad questions into measurable, investigable questions.
• Write directional predictions and testable hypotheses with scientific reasons.
• Recognise when an inquiry is observational/model-based rather than a controlled experiment.

Recall variables, observations, measurements and the difference between a description and an explanation. Know that not every scientific question can ethically or practically be tested by changing one variable.

An investigable question identifies evidence that could answer it. For a relationship test, name the independent variable (changed/compared) and dependent variable (measured). A prediction states the expected pattern. A hypothesis makes a testable relationship claim and usually includes a scientific reason.

Strong form: “How does water temperature affect the time required for a fixed mass of soluble tablet to dissolve?” Prediction: “As temperature increases, dissolving time will decrease.” Hypothesis adds why. Keep claims within what the planned evidence can test.

• Any question is investigable. Evidence must be measurable/observable and feasible.
• A hypothesis is a guess. It is a testable, reasoned explanation/relationship.
• A prediction must be correct. It must be testable; evidence can contradict it.
• All science requires changing one variable. Observational studies and model tests are also scientific inquiries.

1. Identify IV/DV in a temperature–reaction question.
2. Rewrite “Which fertiliser is best?” to define measurable growth and conditions.
3. Add a direction to a prediction.
4. Add scientific reasoning to turn the prediction into a hypothesis.

1. Write an investigable question about light and plant growth.
2. Name IV, DV and three controls.
3. Write a directional prediction.
4. Write a reasoned hypothesis.
5. Convert a broad environmental question into an observational inquiry.
6. Evaluate whether a proposed question can actually be answered by the planned data.

A student wants to test “Does social media harm sleep?” Design a Year 9-appropriate, ethical investigable question that avoids claiming more causation than the feasible data can establish. Explain what type of evidence it could and could not provide.

1. What makes a question investigable? It can be answered with obtainable, relevant observations or measurements.
2. What makes a hypothesis strong? A testable relationship plus a scientific reason.
3. Can evidence reject a hypothesis? Yes; that is a useful scientific outcome.
4. Must every inquiry manipulate a variable? No; some investigate naturally occurring patterns.

1. Rewrite a vague question into a measurable investigation and identify variables.
   Specify what changes/compares, what is measured, and enough conditions to make the question clear.
2. Write a prediction and hypothesis for a supplied investigation.
   Prediction = expected direction; hypothesis = direction plus scientific reasoning.
3. Evaluate whether an observational dataset can establish causation.
   State what relationship it can show and what uncontrolled explanations remain.

• I can identify variables.
• I can make a vague question measurable.
• I can distinguish prediction from hypothesis.
• I can match claims to evidence type.

Exit ticket: Turn “Does temperature matter?” into an investigable question and hypothesis.

Australian Curriculum v9.0 — AC9S9I01: investigable questions, predictions and hypotheses.

Victoria Levels 9–10 — VC2S10I01: Exact.

NSW Stage 5 — SC5-WS-02: Exact develops questions and hypotheses for scientific investigation.

• AC9S9I02 investigations
• AC9S9I03 measurement

• Australian Curriculum v9.0
• Victorian Curriculum F–10 Version 2.0
• NSW Science 7–10 Syllabus (2023)

Curriculum equivalents for Develop investigable questions, reasoned predictions and hypotheses to test relationships...

Mapped skill: develop investigable questions, reasoned predictions and hypotheses to test relationships and develop explanatory models

These references identify matching or closely related learning. Curriculum sequence, terminology and depth vary, so teachers should use the mapped skill and lesson difficulty to confirm suitability.

Australian Curriculum v9.0 is the canonical source for this SkillrHub lesson. Victoria and NSW entries name the closest published state codes or outcomes; international entries are planning references rather than claims of identical curricula.