Year 8 Science • AC9S8I02 • Authored homework
Plan a Reproducible Investigation
Plan fair and reproducible investigations by identifying variables, controls, repeated trials, safety and useful data collection. Show reasoning in full sentences where useful, and check calculations or conclusions before finishing.
Part A
Short-answer questions
Write an investigable question about how light level affects plant growth.
Identify the independent variable, dependent variable and two controlled variables for testing salt concentration and seed germination.
What is the difference between a prediction and a hypothesis?
Why should a method include repeated trials?
Write one safety rule for heating water in a classroom investigation.
Explain why sample size matters when comparing two groups.
Name one piece of equipment needed to measure temperature accurately.
Write a control condition for testing whether fertiliser affects plant height.
What makes a method reproducible for another class?
Why should a data table be planned before the experiment begins?
Part B
Long-answer questions
Design a fair test to investigate how the height of a ramp affects the distance a toy car travels. Include variables, equipment, method, repeats and safety.
A group wants to test whether sugar dissolves faster in warm water. Improve their method so it is fair, safe and reproducible.
Write a hypothesis for an investigation about exercise and heart rate, then explain how you would collect reliable data.
Compare two methods for testing absorbency of paper towels and decide which is more reproducible.
Plan a data table for an investigation into temperature and dissolving time. Explain why each column is needed.
Explain how risk assessment changes when using glassware, hot water or moving objects.
A student changes both water temperature and amount of stirring. Explain why this weakens the investigation and how to fix it.
Describe how to use a control group when testing a claim about plant fertiliser.
Write a step-by-step method another student could follow exactly to test a simple causal relationship.
Evaluate whether a proposed method with one trial and no controlled variables can support a strong conclusion.
Part C
Research and understanding task
Research one simple school science investigation online or in a textbook. Rewrite its method so it clearly identifies variables, controls, repeats, safety and the exact data to collect.