Lesson 3: When Samples Go Wrong
About 30 minutes — Discussion-based lesson
What You Will Learn
This lesson covers:
- Selection bias: your sample systematically excludes certain people
- Self-selection bias: only people with strong opinions respond
- Survivorship bias: you only see the successes, not the failures
- Famous sampling failures: the 1936 Literary Digest poll
Selection bias: your sample systematically excludes certain people
This section covers the key ideas about selection bias: your sample systematically excludes certain people. Discuss with your group or family and explore the concepts together.
Self-selection bias: only people with strong opinions respond
This section covers the key ideas about self-selection bias: only people with strong opinions respond. Discuss with your group or family and explore the concepts together.
Survivorship bias: you only see the successes, not the failures
This section covers the key ideas about survivorship bias: you only see the successes, not the failures. Discuss with your group or family and explore the concepts together.
Famous sampling failures: the 1936 Literary Digest poll
This section covers the key ideas about famous sampling failures: the 1936 literary digest poll. Discuss with your group or family and explore the concepts together.
Check Your Understanding
1. What is selection bias?
2. What is self-selection bias?
3. What is survivorship bias?
4. What happened with the 1936 Literary Digest poll?
Key Takeaways
- Selection bias: your sample systematically excludes certain people
- Self-selection bias: only people with strong opinions respond
- Survivorship bias: you only see the successes, not the failures
- Famous sampling failures: the 1936 Literary Digest poll