Correlation
Measure and interpret relationships between variables
Start with the basics and progress through 5 lessons. Each lesson builds on the previous one.
0 of 5 lessons done
In This Topic (5 lessons)
Introduction to Correlation
Learn how to identify and interpret relationships between two variables using correlation.
Correlation Coefficient
Learn how to measure the strength and direction of a linear relationship between two variables using the correlation coefficient r.
Interpreting Correlation
Read the strength and direction of a correlation from r and from a scatter plot, and describe it in a clear sentence.
Correlation vs Causation
Learn why two variables that rise and fall together do not always cause each other, and how scientists actually prove cause and effect.
Correlation Word Problems
Solve real correlation problems: compute r step by step from a small data set, interpret it in context, judge causal claims and see how an outlier changes r.
Correlation measures the strength and direction of a relationship between two variables. Understanding correlation, its limitations, and the difference from causation is essential for data interpretation.
What You'll Learn
- Calculate correlation coefficient
- Interpret correlation strength and direction
- Distinguish correlation from causation
- Identify outlier effects on correlation
- Apply to real-world data
Frequently Asked Questions
What is the correlation coefficient?
A number from -1 to +1 measuring linear relationship strength. ±1 is perfect, 0 is no correlation.
What does correlation vs causation mean?
Correlation shows two variables move together; it does NOT mean one causes the other.
What affects correlation?
Outliers, non-linear relationships, and restricted ranges can all distort correlation measurements.