Correlation

Correlation is a descriptive statistical technique whereby the relationship between pairs of variables is assessed. The strength of the association between two variables can be determined either qualitatively, with a scatterplot, and/or quantitatively, with a correlation coefficient. A scatterplot is a two-dimensional graph with one variable plotted on each axis, whereby the slope of the least squares regression line (i.e., a linear ‘fit’ through the maximum point cluster) indicates the overall direction and strength of the association. If the linear trend of ordered pairs is sloped upward (downward) from the origin and toward the right, the correlation between the two variables is positive (negative); no slope indicates a neutral relationship, and the variables are unrelated. The closer the data points cluster to this line, the ...