|
||||||
Section
4: Correlation and Regression Scatterplots Correlation of Damages Regression Equation Relationship of Awards |
ScatterplotsIn exploring the relation between two reasonably well-behaved quantitative variables, much of what is useful about correlation and regression can be observed visually through the use of scatterplots.
The plot in a illustrates a perfect positive linear correlation. All data points fit on an upward-sloping straight line. The plot in b illustrates a perfect negative linear correlation. All data points fit on a straight line, but this line slopes downward. A correlation coefficient measures the degree of association, denoted in the figure by r. This measure of correlation is often called Pearson's correlation coefficient, after its originator. In a perfect linear correlation, the correlation coefficient, r, is +1 for a positive correlation and -1 for a negative correlation. In plot c, the eye detects no correlation. And in plot d a correlation exists, but it is not linear. |
|||||
|
|
|
Comments to ted@teddy.law.cornell.edu | ||
Last updated: September 2002 |