Assumptions of Regression

The specific assumptions underlying a regression analysis are the same as the assumptions that underly the correlation coefficient. As a reminder, they are:

1. There is a linear relationship in the population between the y variable and the x variable.
2. The population distributions from which the x and y variable come from are normally distributed.
3. The standard deviations of the population y values about the line are equal for each value of x. In other words, each of these normal distributions of y values has the same shape and spread about the line. In statistics, we call this homoscedasticity.

4.The data is at least ordinal data. It could also be interval or ratio.