Year 9 Science · Unit 4 · Lesson 14

Causal vs Correlational Relationships

Challenge Worksheet

Name

Date

Class

Learning Goals

Critically judge whether a claim has confused correlation with causation.
Justify the role of confounding variables, controlled experiments and large datasets in proving cause.
Design an investigation that could move a finding from correlation toward a tested cause.

Warm Up

Odd one out

Circle the item that does not belong in each group. Then explain why it doesn't fit in the answer column.

#	Group	Your answer (odd one + reason)
1	Positive correlation Negative correlation No correlation Favourite correlation
2	Controlled experiment Plausible mechanism Consistent across studies Sounds convincing
3	Confounding variable Coincidence A real cause A correlation that just moves together
4	Large sample Rules out chance Statistically tested Proves cause by itself

Go Deeper

Evaluate the claim

An advertisement claims...

"In a survey of 500 customers, people who take our daily multivitamin reported getting fewer colds than people who do not. This proves our multivitamin prevents colds. Buy a year's supply today!"

(a) Explain why this survey shows a correlation but does not prove that the multivitamin causes fewer colds. Refer to the idea of a confounding variable.

Challenge 3 marks

(b) Smoking was once dismissed as "only correlated" with lung cancer. Describe the kinds of evidence scientists needed to gather before they could claim smoking causes cancer.

Challenge 3 marks

(c) Design a controlled experiment that could properly test whether the multivitamin causes fewer colds. State the variable you would change, the variable you would measure, two variables you would control, and explain how a large dataset and statistics would help validate your result.

Challenge 4 marks

Wrap Up

In one sentence, what was the main idea of this lesson?