AP Statistics Flashcards: Correlation
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 14 cards to help you master important concepts.
Does a correlation coefficient, r, have units?
No, the correlation, r, is a unit-free measurement.
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Does a correlation coefficient, r, have units?
No, the correlation, r, is a unit-free measurement.
How is the strength of a linear association determined from the correlation coefficient, r?
The strength is determined by how close the absolute value of r is to 1; values closer to 1 or -1 indicate a stronger linear association.
What does a correlation value of r = 0 indicate?
A value of r = 0 indicates that there is no linear association between the variables.
How do you interpret a correlation coefficient that is close to -1?
A correlation, r, close to -1 indicates a strong, negative linear association.
What two aspects of a linear relationship does correlation describe?
Correlation gives the direction (positive or negative) and quantifies the strength of a linear association.
What is the most common way to determine the correlation coefficient for a linear relationship?
The correlation coefficient is most commonly determined using technology, such as a calculator or statistical software.
What is the correlation coefficient, r?
The correlation, r, is a value that gives the direction and quantifies the strength of a linear association.
What is the most critical limitation to remember when interpreting a strong correlation?
It is essential to remember that correlation does not necessarily imply causation.
If a dataset has a correlation of r = 0.98, does this guarantee that a linear model is appropriate?
No, a correlation coefficient close to 1 or -1 does not necessarily mean a linear model is appropriate.
If a study finds a strong negative correlation between hours of sleep and stress levels, can we conclude that less sleep causes stress?
No, we cannot conclude causation from this observation because correlation does not necessarily imply causation.
How do you interpret a correlation coefficient that is close to 1?
A correlation, r, close to 1 indicates a strong, positive linear association.
What is the range of possible values for the correlation, r?
The correlation, r, is always a value between -1 and 1, inclusive.
How is the direction of a linear association determined from the correlation coefficient, r?
The sign of r gives the direction of the association; a positive r indicates a positive association, and a negative r indicates a negative association.
What is the primary purpose of determining and interpreting correlation?
The purpose is to determine and interpret the direction and strength of a linear relationship between two variables.