LEARN · EXPLAIN · REVISE

An observational survey reports the displayed positive correlation between study time and score. Does it prove a causal effect?

Read the idea, work independently, then explain what changed.

TOPIC 01

Statistical analysis of paired data: mixed review

A mixed assessment: identify the method, justify it and revise your reasoning.

Use one hint at a time. A correction explains what changed, not just the final answer.

01 / Transfer#Your turn

r=0.1

Both centered sums of squares must be positive; correlation measures linear association and does not establish causation.

Skills and prerequisite lessons

Working and explanation

BUILD THE REASONING

Hint 1

Use the paired-data summaries, preserving which observations belong together.

Hint 2

Consider confounding and study design.

Worked solution

Use the paired-data summaries, preserving which observations belong together.
Apply the stated relation and retain its conditions.
$\text{Prior preparation may influence both variables.}$
The size of an observational correlation does not replace a causal design or justified control of confounding.

The requested relation or conclusion is shown below.

\text{association does not establish causation}

Checks and common pitfalls: The size of an observational correlation does not replace a causal design or justified control of confounding.

Reasoning checklist · self / teacher assessment

Think first. Reveal a hint when the class is ready.

Teacher preparation and assessment