# Design Matrix — Scaling Covariates

**Design Matrix — Scaling Covariates**

Although extreme ranges of covariates might appear biologically unreasonable, MARK scales all the values in the design matrix to values between -1 and 1. The user is not required to scale design matrix entries.

Individual covariates can also be standardized for specific models to have a value of zero, but MARK also automatically scales individual covariate values to the range -1 to 1.