When I build a regression model, which is considered most important:
- removing insignificant variables,
- checking jfor multicollinearity and removing those variables that contribute to it,
- multiple R-Squared,
- or something else?
If I have to take care of all of the above, what should be my order of preference?
If I want to evaluate the model, is there is hard and fast rule that says residuals should be normally distributed?