Science · Year 7 · Scientific Investigations · Term 3

The Scientific Method: Question and Hypothesis

Students will learn to formulate testable questions and construct clear, falsifiable hypotheses.

• ACARA Content Descriptions
• AC9S7I01
• AC9S7I02

About This Topic

Formulating testable questions and clear, falsifiable hypotheses anchors scientific investigations for Year 7 students. They learn to differentiate scientific questions, which invite evidence-based answers through experiments or observations, from non-scientific ones rooted in opinion or belief. For example, students transform "Why is the sky blue?" into "Does scattering of light by air particles cause blue skies during the day?" They then craft hypotheses like "If we add fertilizer to soil, then bean plants will grow taller than controls because nutrients speed growth."

These practices align with AC9S7I01 and AC9S7I02, which focus on planning investigations with fair tests and variables. Students critique hypotheses for clarity and testability, fostering skills essential across science strands, from biological growth to physical forces.

Active learning benefits this topic greatly. When students generate questions from shared observations, swap and revise peers' hypotheses in groups, or role-play tests, they grasp the iterative process firsthand. This builds ownership, exposes flaws through discussion, and makes abstract inquiry concrete and engaging.

Key Questions

1. Differentiate between a scientific question and a non-scientific question.
2. Construct a testable hypothesis for a given observation.
3. Critique a hypothesis for its clarity and falsifiability.

Learning Objectives

• Formulate at least two testable scientific questions based on a given observation.
• Construct a falsifiable hypothesis for a given scientific question, identifying independent and dependent variables.
• Critique three given hypotheses, identifying weaknesses in clarity or testability.
• Differentiate between scientific and non-scientific questions using provided examples.

Before You Start

Observing and Describing

Why: Students need to be able to make careful observations to generate questions and identify phenomena to investigate.

Identifying Variables (Introduction)

Why: A basic understanding of what can be changed or measured in a situation is helpful before formally defining independent and dependent variables.

Key Vocabulary

Testable Question	A question that can be answered through observation or experimentation, focusing on measurable or observable phenomena.
Hypothesis	A proposed explanation for an observation, stated as a clear, concise, and falsifiable prediction that can be tested through investigation.
Falsifiable	The characteristic of a hypothesis that it can be proven wrong through experimental results or further observation.
Independent Variable	The factor that is intentionally changed or manipulated by the investigator in an experiment.
Dependent Variable	The factor that is measured or observed in an experiment; it is expected to change in response to the independent variable.

Watch Out for These Misconceptions

Common Misconception

A hypothesis is just an educated guess with no structure.

What to Teach Instead

Hypotheses require an 'If...then...because...' format to predict and explain. Pair critiques help students spot vague guesses and rebuild them testably, as groups test mini-versions to see what works.

Common Misconception

All 'why' questions are scientific.

What to Teach Instead

Many 'why' questions seek causes but need rephrasing for testing, like 'What makes seeds sprout faster?'. Sorting tasks in small groups let students debate and refine collaboratively, revealing patterns in testability.

Common Misconception

Hypotheses aim to be proven correct.

What to Teach Instead

Strong hypotheses are falsifiable, open to disproof. Whole-class debates on sample hypotheses shift this view, as students propose counter-tests and see science's strength in potential failure.

Active Learning Ideas

Pairs: Observation to Hypothesis Chain

Partners select a classroom phenomenon, like pencil dissolving in water. One writes a testable question; the other adds an 'If...then...because...' hypothesis. They chain three more, refining each for clarity. Pairs share chains class-wide.

25 min·Pairs

Small Groups: Question Sorting Carousel

Prepare cards with 20 questions, half scientific, half not. Groups sort into categories, justify choices, then rotate to review and debate prior sorts. Conclude with class vote on trickiest items.

40 min·Small Groups

Whole Class: Hypothesis Peer Review Gallery

Students write hypotheses for provided scenarios on posters. Gallery walk: view others, add sticky-note feedback on testability. Writers revise based on notes and present improvements.

35 min·Whole Class

Individual: Falsifiability Quick-Fire

Give observation prompts. Individually draft hypotheses, then pair to check if falsifiable by proposing disproof tests. Regroup to share strongest examples.

30 min·Individual

Real-World Connections

• Medical researchers formulate hypotheses about new drug efficacy, such as 'If patients receive Drug X, then their blood pressure will decrease more than patients receiving a placebo, because Drug X targets specific receptors.' This guides clinical trials.
• Agricultural scientists develop hypotheses to improve crop yields, for example, 'If soil is treated with Bio-fertilizer Y, then plant growth will increase because Bio-fertilizer Y provides essential micronutrients.' This informs farming practices.
• Environmental engineers investigate pollution, posing questions like 'Does the presence of microplastics in river water correlate with a decrease in aquatic insect populations?' Their hypotheses guide sample collection and analysis.

Assessment Ideas

Quick Check

Present students with three scenarios: a scientific question, a non-scientific question, and a statement of opinion. Ask them to label each and write one sentence explaining their choice for the scientific question.

Exit Ticket

Provide students with an observation, such as 'Plants in sunlight seem to grow faster than plants in shade.' Ask them to write one testable question and one corresponding hypothesis for this observation, identifying the independent and dependent variables.

Peer Assessment

Students write a hypothesis for a given scientific question. They then swap hypotheses with a partner. Each student critiques their partner's hypothesis, answering: Is it clear? Can it be tested? Is it falsifiable? Partners provide feedback on one specific area for improvement.

Frequently Asked Questions

What makes a Year 7 scientific question testable?

Testable questions specify variables for investigation, such as 'Does light color affect plant growth rate?' rather than vague 'Why do plants grow?'. They allow data collection or experiments with controls. Teach by modeling refinements from student ideas, ensuring questions predict measurable outcomes under Australian Curriculum standards.

How do you construct a falsifiable hypothesis?

Use 'If [independent variable change], then [dependent variable effect] because [reason]'. For example, 'If salt is added to water, then ice will melt slower because salt lowers freezing point'. Critique for clarity: can it be disproven? Group practice refines this, linking to AC9S7I02 fair test planning.

How can active learning help students master questions and hypotheses?

Active strategies like peer reviews and gallery walks engage students in generating, critiquing, and revising. Pairs or groups expose weak ideas quickly through discussion, building skills iteratively. Hands-on chains from observations make processes real, boosting retention and confidence for independent investigations.

What are common errors in Year 7 hypotheses?

Errors include non-testable claims, missing predictions, or unstated reasons, like 'Plants need water' without variables. Students confuse guesses with hypotheses. Address via sorting carousels: collaborative sorting and defense clarify criteria, aligning with AC9S7I01 for precise planning.