Year 9 Science · Unit 4 · Lesson 19

Evidence and Scientific Explanations

Challenge Worksheet

Name
Date
Class

Learning Goals

Warm Up

Because… chain

Fill in the five missing steps to complete the pathway from hypothesis to established scientific knowledge. Use the word bank below to guide you.

peer review repeated data CER conclusion patterns independent replications
Scientist forms hypothesis and designs experiment with controlled variables
→
Data collected; scientist analyses for
→
Scientist writes
→
Manuscript submitted; expert reviewers check method and data (
→
Other scientists replicate study; multiple
→

Final outcome (what happens when new contradicting evidence emerges):

Go Deeper

Media claim

A news website reports: "Scientists say phones damage hearing — new study proves it." The article describes a single study of 40 university students who reported higher perceived hearing difficulty after using earphones at high volume for one week, compared with 40 students who did not. The study was not yet published in a journal.

(a) List at least three questions a scientifically literate reader should ask about this study before accepting the headline claim. Explain why each question matters.

Challenge 3 marks

(b) Describe what strong evidence for this claim would look like. In your answer refer to: sample size, control group, measurement method, and peer review.

Challenge 4 marks

(c) Explain the difference between a single study's finding and established scientific knowledge. Use an example from the waves unit — such as the relationship between wave frequency and energy — to illustrate your answer.

Challenge 4 marks

Wrap Up

In one sentence, why does science require multiple independent replications before a finding becomes established knowledge?

HSCScience · Year 9 Science · Unit 4 · Lesson 19 · Challenge Worksheet