Track C — Chapter 14 Problem Set (Repeated-Measures ANOVA)

This problem set gives you practice with repeated-measures (within-subjects) ANOVA. You will analyze designs where the same participants are measured at 3+ time points.

Prerequisite

Complete the Chapter 14 lab first:

How to run

From the repository root:

python -m scripts.psych_ch14_problem_set

Run a single exercise:

python -m scripts.psych_ch14_problem_set --exercise 1
python -m scripts.psych_ch14_problem_set --exercise 2
python -m scripts.psych_ch14_problem_set --exercise 3

What you should submit

For each exercise:

  1. Report the repeated-measures ANOVA result (F, df, p).

  2. Report partial eta-squared (np2) as the effect size.

  3. Write a 2–4 sentence interpretation in APA-style language, including: - whether there is evidence of change over time, - the direction/pattern of means (e.g., increasing, flat, etc.), - practical interpretation of the effect size.

Exercises

Exercise 1 — Clear time effect

A dataset with three time points and a strong change over time.

Goal: - You should see a significant time effect and a large effect size.

Exercise 2 — No true time effect

A dataset with four time points where the population means are equal.

Goal: - You should see a non-significant time effect and a tiny effect size.

Exercise 3 — Correlated measurements (sphericity risk)

A dataset with four time points and correlated within-subject errors (realistic longitudinal structure).

Goal: - You should still detect a time effect. - Discuss sphericity conceptually (and if the output includes sphericity/GG info, comment on it).