What are Pearson's r and scatterplots?
Home > What are Pearson's r and scatterplots?
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Sometimes we want to know whether
two variables are related to one another. If they are related, we want to
know how much. Is there a strong relationship between two variables or is it
a weak relationship? What is the direction of the relationship?
When one variable goes up, does the
other go down? Pearsonís r can help us with that. Pearsonís r is a statistic
that helps you understand the strength of the linear relationship between
Close to 1, there is a strong relationship between your
Close to 0, there is a weak relationship between your
Positive (+), as one variable increases in value, the
second variable also increases in value. This is called a positive
(-), as one variable increases in value, the second variable decreases in
value. This is called a negative correlation.
These are graphs that often
accompany the Pearsonís r statistic. These graphs help us understand the
relationship between the two variables. They have lots of dots. Each dot
signifies a data point that represents values of both variables.