(Answered) Dummy variables for regression analysis can take on a value of either -1 or +1.Question 6…

➤ How does using -1/+1 coding affect the regression intercept and coefficients?
With -1/+1 coding, the intercept equals the overall (grand) mean across groups. Each coefficient represents half the difference between the two coded groups, so you must multiply a coefficient by two to get the full group difference. Interactions become centered and more interpretable, reducing multicollinearity with main effects.