Lesson 9
R-squared
Big question
How much of the outcome's variation does the regression explain?
Lesson progress
Complete checkpoints as you learn
Learning objectives
- Explain r-squared in plain language.
- Use the main concept correctly.
- Connect the lesson idea to a formula, graph, Python result, or real example.
Simple explanation
How much of the outcome's variation does the regression explain?
Key terms
Example
How much of the outcome's variation does the regression explain?
Python walkthrough
Interactive activity
R-squared visualizer
Compare how much variation is explained by models with different R-squared values.
Higher R-squared means more sample variation in y is explained by x. It measures fit, not whether the relationship is causal.
R-squared visualizer
Compare how much variation is explained by models with different R-squared values.
Higher R-squared means more sample variation in y is explained by x. It measures fit, not whether the relationship is causal.
Try it yourself
Write one plain-English sentence explaining the main idea from this lesson.
Common mistakes
Check these before you move on.
R-squared measures fit. It does not say whether x causes y.
Quick quiz
What is the main idea of R-squared?
Key takeaway
Use this lesson idea in a cautious, evidence-based regression interpretation.