On Monday, February 27, 2017 at 9:07:45 AM UTC-5, Sushma Dhital wrote:
> I read that independent categorical variable should be treated as factors, is it true?
Yes, Factors are categorical explanatory variables (e.g., sex, marital status), and Covariates are continuous (or at least quantitative) explanatory variables (e.g., age, body weight).