On this site I have written quite a lot about regression analysis.
But what is regression analysis?
Briefly, regression analysis is a set of methods for relating dependent variables to independent variables. In the vast majority of regressions there is one dependent variable and any number of independent variables. There are a lot of types of regression analysis. But, you may ask
What is regression analysis for?
The main thing that makes regression analysis special is the idea of controlling for other variables. The mathematics behind this are interesting to geeks like me, but the basic idea is that of holding other variables constant. It is a way of looking at the relationship between the dependent variable and each independent variable while holding the values of the other independent variables constant.
“OK”, you say
But what is regression analysis used for?
And the answer is: Almost everything!
How do voting preferences relate to sex?
How do college grades relate to age?
How does income relate to age, sex, ethnicity and race?
How does the likelihood of getting cancer relate to smoking?