AC9S6I02: Plan and conduct repeatable investigations to answer questions including, as appropriate, deciding the variables to be changed, measured and controlled in fair tests; describing potential risks; planning for the safe use of equipment and materials; and identifying required permissions to conduct investigations on Country/Place

independent variable

the factor deliberately changed in a fair test

dependent variable

the outcome measured or observed

controlled variable

another factor kept consistent so it does not confound the test

validity

how well a method fairly tests the intended question

reliability

how consistently a pattern appears across repeated evidence

precision

how closely repeated measurements agree with one another

resolution

the smallest increment an instrument can detect or display

hazard

a source or situation with potential to cause harm

risk control

an action that reduces the likelihood or consequence of harm

confounding variable

an uncontrolled factor that changes alongside the tested factor

control group

a baseline condition without the tested treatment

Reliable routine

1. Write the answerable investigation question.
2. Identify changed, measured and controlled variables.
3. Seek permissions and assess hazards, harms and controls.
4. List equipment with quantities and suitable measuring resolution.
5. Write an ordered method with exact setup, timing, units and repetitions.
6. Prepare a labelled table, conduct consistently and record raw data.
7. Check means, spread and anomalies; evaluate reliability, validity and limitations.

The planning chain

A strong investigation links an answerable question to a prediction, variables, permissions, risk controls, equipment, numbered method, measurements, repetitions, table and evidence-based conclusion.

Variables and fair tests

The independent variable is deliberately changed; the dependent variable is measured; controlled variables are other factors kept consistent. A control group provides a baseline without the treatment where appropriate.

Make the method repeatable

State materials and quantities, exact setup, ordered actions, timing, measurement endpoints, units, instrument resolution and number of trials. “Do it again” cannot repair a vague method.

Measure and record well

Choose equipment suited to the quantity and record only the detail its scale or display supports. Prepare table headings with the changed condition, trial numbers, measured quantity and unit before collecting data.

Reliability, validity, precision and resolution

Reliability concerns whether a pattern is supported when an investigation is repeated; validity concerns whether the design fairly answers the question; precision concerns close agreement among repeated measurements; resolution is the smallest increment an instrument detects or displays. More repeats reveal spread but do not fix a confound.

Repetitions and unusual results

Use at least three trials where practical, calculate a useful mean and inspect spread. Investigate anomalies, repeat if possible and document decisions instead of silently deleting inconvenient values.

Risk and safe practice

Identify the hazard, possible harm and specific control. Use age-appropriate equipment, supervision and protective measures. Stop when conditions differ from the approved safe plan.

Permissions on Country/Place

Before fieldwork, seek required administrative and cultural permissions. Consult relevant Traditional Owners or land councils and follow guidance about sensitive locations, access, collecting, photography, data and sharing.

Choosing an approach

Fair tests suit causal questions; systematic field observations suit patterns in place; research supplies existing evidence; digital tools support data collection; simulations explore unsafe or inaccessible systems. Each approach has limits.

Plan critique

Ask: Can the question be answered? Is one factor changed? Are alternatives controlled? Are equipment, units and steps explicit? Are repeats sufficient? Are safety and permissions addressed? Does the table capture the needed evidence?

• The controlled variable is the result. The dependent variable is measured; controlled variables are other influential conditions kept consistent.
• All variables must be identical. The independent variable must change deliberately; the other influential conditions should remain consistent.
• Repeatable means every result is exactly the same. Small variation is expected. Repeatability means enough detail to reproduce the method and examine whether a consistent pattern occurs.
• Repeating a test makes it valid. Repeats support reliability but cannot repair a confound or systematically unfair comparison.
• Public access removes the need for permission on Country/Place. Access, collecting, recording and sharing may require separate administrative and culturally informed permissions.

• How many repetitions are enough? Use at least three where practical, and more when natural variation or measurement uncertainty is substantial.
• Does a precise instrument guarantee a good test? No. Fine resolution does not guarantee valid design, accurate calibration or reliable results.
• Should an unusual result be deleted? Not automatically. Check, repeat and document a defensible evidence-based decision.
• Who can give cultural guidance for fieldwork on Country/Place? The relevant Traditional Owners or land council; authority and appropriate practice are specific to place.

• Name the changed, measured and controlled variables precisely.
• Use quantities, units, timing and measurement endpoints in methods.
• Separate comments about validity, reliability, precision and instrument resolution.
• Link every risk control to a stated hazard and possible harm.
• State and follow required permissions before work on Country/Place.
• Use repeats and means without hiding spread or unexplained anomalies.

• Support: work with one short example, highlighted evidence and a structured response frame.
• Core: complete an unseen example independently and justify the decisive evidence.
• Extend: compare plausible alternatives, explain limitations and create a new example within the Year 6 boundary.

Plan a safe paper-helicopter investigation with variables, controls, units, repetitions and enough procedural detail for another group to repeat it.

Evidence of mastery: The student plans a safe, permitted, fair and repeatable investigation, records suitable measurements and evaluates validity, reliability, repeat-measurement precision and instrument resolution as distinct qualities.

Project the HTML teaching view, with classroom-sized sections drawn directly from this topic guide.

Learn from the Topic Guide and Classroom View, complete the Worksheet, use Practice for supported feedback, then take the separate Test when ready.

Curriculum equivalents for Plan and conduct repeatable investigations to answer questions including, as...

Mapped skill: plan and conduct repeatable investigations to answer questions including, as appropriate, deciding the variables to be changed, measured and controlled in fair tests; describing potential risks; planning for the safe use of equipment and materials; and identifying required permissions to conduct investigations on Country/Place

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.

Australian Curriculum Version 9.0

• AC9S6U01: Physical Conditions and Organism Survival
• AC9S6U02: Earth, Planets and the Solar System
• AC9S6U03: Energy Transfer and Transformation in Circuits
• AC9S6U04: Reversible and Irreversible Changes
• AC9S6H01: Scientific Advances through Collaboration and Technology
• AC9S6H02: Scientific Knowledge in Community Decisions