Regression analysis is a technique of measuring or estimating the relationship among variables.
Regression analysis provides Estimates of values of the Dependent Variable From the value of the independent variable.
The Regression line describes the average relationship existing between x and y.
The Difference between Correlation analysis and Regression Analysis
- Correlation coefficient is a measure of degree of Co-variability between x and y While Objective of Regression analysis is to study the Nature of Relationship.
- In Correlation analysis both rₓᵧ or rᵧₓ are symmetric (rₓᵧ=rᵧₓ). In Regression analysis bₓᵧ and bᵧₓ are not symmetrical (bₓᵧ =/= bᵧₓ).
- In Correlation analysis we cannot say that one variable is “cause” and the other the “Effect” but in Regression analysis it is possible to study cause and effect relationship.
- There may be a non-sensical correlation which has no practical relevance in Correlation analysis Example Increase in income and Increase in Weight. There is no such things like these on Regression Analysis.
- Correlation coefficient is independent of change in origin and scale. Regression coefficient are independent of change of origin but not of scale.
Correlation coefficient (r) and Regression coefficient are (bₓᵧ and bᵧₓ) always have same sign.