LEARN · EXPLAIN · REVISE

A before/after category table records the same t people twice. Can a standard independent-observation chi-square analysis treat the records as separate people?

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 / Standard#Your turn

t=41

Observations must be independent; expected counts support the supplied large-sample approximation. Rejection is evidence of association, not 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

Check whether rows share participants.

Worked solution

Use the paired-data summaries, preserving which observations belong together.
Apply the stated relation and retain its conditions.
$\text{paired records are dependent}$
The study needs a method for paired categorical outcomes rather than treating repeated people as independent.

The requested relation or conclusion is shown below.

\text{the independent-observation assumption fails}

Checks and common pitfalls: The study needs a method for paired categorical outcomes rather than treating repeated people as independent.

Reasoning checklist · self / teacher assessment

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

Teacher preparation and assessment