Such assumptions may force the fitted relationship away from its natural path at critical points. The GAM suggests a possible curved relationship which may more accurately reflect the progress of the condition.
GAMs work by replacing the coefficients found in parametric models, by a smoother.
Classical Linear Model 2. Generalized Linear Model 3. Additive Model 4. The classical linear model is the simplest model that can be used to relate the response variable to the explanatory variables. Given a set of explanatory variables the response variable, Y, is normally distributed.