What does a negative r-value indicate in Pearson's correlation?

A negative r-value in Pearson's correlation indicates a negative linear relationship between the two variables. This means that as one variable increases, the other variable tends to decrease, reflecting an inverse relationship. In statistical practice, a negative correlation suggests that the variables move in opposite directions, which can be crucial for understanding how they interact with each other.

For instance, in a study evaluating the relationship between hours spent studying and number of hours spent watching television, you might find a negative r-value. This indicates that increased study time correlates with less television watching, highlighting the competitive nature of the two activities.

The strength of this negative correlation can vary, ranging from a weak negative relationship (closer to zero) to a strong negative relationship (closer to -1). Understanding this concept is essential for analyzing data and drawing meaningful conclusions in research and practical applications.