What Is Correlation? A Guide for Beginners
ContentComparing studiesGrammar CheckerCorrelation and independencecorrelationWhat Is a Correlation?How do you know if a study is correlational?
The Pearson correlation coefficient (r) is the most common way of measuring a linear correlation. It is a number between –1 and 1 that measures the strength and direction of the relationship between two variables. The correlation coefficient ( r ) indicates the extent to which the pairs of numbers for these two variables lie on a straight line. Values over zero indicate a positive correlation, while values under zero indicate a negative correlation. A correlation coefficient, often expressed as r, indicates a measure of the direction and strength of a relationship between two variables.
For example, with demographic data, we generally consider correlations above 0.75 to be relatively strong; correlations between 0.45 and 0.75 are moderate, and those below 0.45 are considered weak. For this kind of data, we generally consider correlations above 0.4 to be relatively strong; correlations between 0.2 and 0.4 are...