Stage 8 - Q1 - 2 marks
Why must an investigation have a clear question?
Hint
Consider whether any collected number would answer the aim.
Stage 8 - Q2 - 2 marks
A study compares two seed types. What label must accompany each plant height?
Hint
The comparison depends on knowing which group produced each value.
Stage 8 - Q3 - 2 marks
Suggest a consistent unit for timing a short puzzle.
Hint
Choose a unit suitable for the expected duration.
Stage 8 - Q4 - 2 marks
A recording sheet has no date. Why might that matter in a plant study?
Hint
Think about whether height changes during the investigation.
Stage 8 - Q5 - 3 marks
State two controls for comparing the growth of two seed types.
Hint
Change the seed type while keeping other growth conditions comparable.
Stage 8 - Q6 - 3 marks
Four measured lengths are 12, 13, 120 and 14 cm. What should the investigator do with 120?
Hint
An unusual value is a reason to check, not automatic proof of error.
Stage 8 - Q7 - 3 marks
A class compares running times, but one group runs uphill. Explain and improve the design.
Hint
Look for a difference other than the grouping variable.
Stage 8 - Q8 - 3 marks
A pilot produces different counts from two observers. Give a practical next step.
Hint
Both observers need to count the same kind of event.
Stage 8 - Q9 - 3 marks
A study finds taller pupils tend to have larger shoe sizes. Does making a pupil taller prove that shoe size changes?
Hint
An observed relationship can have other explanations.
Stage 8 - Q10 - 5 marks
Challenge: design a fair investigation of whether a new queue layout reduces waiting time. Include comparison periods, measurement, sampling and a limitation.
Hint
Aim to compare the layouts without confusing them with different days or levels of demand.