What does a correlation coefficient measure?

The correlation coefficient quantifies the strength and direction of a linear relationship between two variables. A positive correlation indicates that as one variable increases, the other tends to increase as well, while a negative correlation suggests that as one variable increases, the other tends to decrease. The value of the correlation coefficient ranges from -1 to 1, where -1 signifies a perfect negative correlation, 0 indicates no correlation, and 1 represents a perfect positive correlation. This measure is essential in statistics and research as it helps determine how closely related two variables are, which can inform decision-making processes and analyses in various fields.