Skip to course content
Free statistics course

Basic Statistics for Data Analysis / Module 9

Module 9 worksheet

Module 9 Worksheet: Comparing Groups and Effect Sizes

Scenario

You are helping a beginner analyst review a small synthetic dataset. Your job is not to sound impressive. Your job is to make the safest useful statement.

Data

Dataset: group-comparison-summary.csv

group_namesample_sizemean_scorestandard_deviationnotes
No practice quiz486812baseline group
One practice quiz527211small improvement
Three practice quizzes507910stronger improvement
Optional review session288114self-selected group
Required review session55769assigned group

Your Task

Write a cautious group-comparison paragraph using mean, sample size, spread, and one limitation.

Questions

  1. What is the statistical question?
  2. What is the unit of analysis?
  3. Which variables matter most?
  4. What summary, comparison, or visual check is suitable?
  5. What does the evidence suggest?
  6. What should not be claimed?
  7. What limitation should be mentioned?

Write Your Conclusion

Write two to four careful sentences. Use plain English. Do not use words like proves, guarantees, or always unless the evidence truly supports them.

Self-Check

  • Did I name the question?
  • Did I use the right denominator or comparison?
  • Did I avoid claiming more than the data can support?
  • Did I mention uncertainty, bias, assumptions, or limits where needed?