Often the questions we ask require us to make accurate predictions on how one factor affects an outcome. If a teacher is asked to work out how time spent writing an essay affects essay grades, it’s ...

It is sometimes desired to fit a second degree polynomial E(y∣ x) = α + β x + γ x 2 to a set of data so that its stationary point will fall in a given region. Methods are shown to calculate a, b, c, ...

The adjusted r-squared is helpful for multiple regression and corrects for erroneous regression, giving you a more accurate correlation coefficient. If you look at the multiple regression we did, ...

Watson (1955) investigated the performance of a regression analysis based on the assumption that the error covariance matrix is σ2γ when it is, in fact, σ2α. In ...