The bivariate Pearson correlation indicates the following: Whether a statistically significant linear relationship exists between two continuous variables. The strength of a linear relationship (i.e., how close the relationship is to being a perfectly straight line)

Pearson’s r can range from -1 to 1. An r of -1 indicates a perfect negative linear relationship between variables, an r of 0 indicates no linear relationship between variables, and an r of 1 indicates a perfect positive linear relationship between variables.

Pearson’s r can range from −1 to 1. An r of −1 indicates a perfect negative linear relationship between variables, an r of 0 indicates no linear relationship between variables, and an r of 1 indicates a perfect positive linear relationship between variables.

The sample correlation coefficient (r) is a measure of the closeness of association of the points in a scatter plot to a linear regression line based on those points, as in the example above for accumulated saving over time.

To interpret its value, see which of the following values your correlation r is closest to:

1. Exactly –1. A perfect downhill (negative) linear relationship.
2. –0.70. A strong downhill (negative) linear relationship.
3. –0.50. A moderate downhill (negative) relationship.
4. –0.30.
5. No linear relationship.
6. +0.30.
7. +0.50.
8. +0.70.

Direction: The sign of the correlation coefficient represents the direction of the relationship. Positive coefficients indicate that when the value of one variable increases, the value of the other variable also tends to increase. Positive relationships produce an upward slope on a scatterplot.

It is known as the best method of measuring the association between variables of interest because it is based on the method of covariance. It gives information about the magnitude of the association, or correlation, as well as the direction of the relationship.

Pearson Correlation – These numbers measure the strength and direction of the linear relationship between the two variables. The correlation coefficient can range from -1 to +1, with -1 indicating a perfect negative correlation, +1 indicating a perfect positive correlation, and 0 indicating no correlation at all.

The sample correlation coefficient, denoted r, For example, a correlation of r = 0.9 suggests a strong, positive association between two variables, whereas a correlation of r = -0.2 suggest a weak, negative association.

This represents a very high correlation in the data. Generally, a value of r greater than 0.7 is considered a strong correlation. Anything between 0.5 and 0.7 is a moderate correlation, and anything less than 0.4 is considered a weak or no correlation.

If the correlation is 0.8, it means that on average, people 1 SD over the mean on X are about . 8 SDs above the average of Y. If the correlation is 0.0, it means that the average Y value for people 1 SD over the average on X is just about 0 SDs over the average of Y, which means that it is just the average of Y.

The linear correlation coefficient of approximately 0.04 suggests that there is no appreciable linear correlation. The coefficient of determination of 0.0016 suggests that perhaps 0.16% (practically none) of the variability of the player score is dependent on age.

As a rule of thumb, a correlation coefficient between 0.25 and 0.5 is considered to be a “weak” correlation between two variables. 2. This rule of thumb can vary from field to field. For example, a much lower correlation could be considered weak in a medical field compared to a technology field.

– if R-squared value < 0.3 this value is generally considered a None or Very weak effect size, – if R-squared value 0.3 < r < 0.5 this value is generally considered a weak or low effect size, – if R-squared value r > 0.7 this value is generally considered strong effect size, Ref: Source: Moore, D. S., Notz, W.

R-squared and the Goodness-of-Fit For the same data set, higher R-squared values represent smaller differences between the observed data and the fitted values. R-squared is the percentage of the dependent variable variation that a linear model explains.

If strength and direction of a linear relationship should be presented, then r is the correct statistic. If the proportion of explained variance should be presented, then r² is the correct statistic.

Simply put, R is the correlation between the predicted values and the observed values of Y. R square is the square of this coefficient and indicates the percentage of variation explained by your regression line out of the total variation.