mean centering & variables scaling
Posted: Tue Mar 19, 2024 5:14 pm
hello. I am planning to use a mixed model when writing my paper. I have three questions:
1. When controlling covariates such as age, years of education, and gender, it is said that gender is treated as a dummy variable because it is nominal. What about age or years of education? Can I check centered?
2. When the level 2 independent variable is a group, mean centering cannot be performed, so can it be treated as a dummy variable in this case as well?
3. When I want to add covariates, is it correct to put the nominal variables in factors and the rest in covariates?
thank you for your help
have a good day.
1. When controlling covariates such as age, years of education, and gender, it is said that gender is treated as a dummy variable because it is nominal. What about age or years of education? Can I check centered?
2. When the level 2 independent variable is a group, mean centering cannot be performed, so can it be treated as a dummy variable in this case as well?
3. When I want to add covariates, is it correct to put the nominal variables in factors and the rest in covariates?
thank you for your help
have a good day.