Stepwise regression

Stepwise regression is a method of choosing the best things to include in an equation that explains the data. Imagine if you have eight pieces of data, such as eight numbers. You can make a math equation, like "a + b + c" that describes all eight pieces of data. Stepwise regression is a way to decide which of the numbers "a" "b" and "c" should be a part of the equation. It starts with the simplest equation (just one number), then it adds one number at a time to see if it makes the equation better. It will keep adding numbers until it can't make the equation any better. That's how it decides what numbers should be included in the equation.