R², or the coefficient of determination, can take values from 0 to 1.
- An R² value of 0 indicates that the model does not explain any variability in the dependent variable, meaning it does not provide any better predictions than using the mean of the dependent variable.
- An R² value of 1 indicates that the model perfectly explains the variability in the dependent variable, meaning all data points lie exactly on the fitted line or curve.
In some cases, particularly with adjusted R², values can also be negative if the model is worse than a model that simply predicts the mean of the dependent variable. However, for the basic R², the range is typically from 0 to 1.