I am trying to model some data, and as part of the modeling, I tried linear model (using
lm function) and non-linear model (using
Model 1: a linear model which has degrees of freedom (df), (AIC) = 2, 2130
Model 2: a non-linear model which has df, AIC= 4, 2128.
Model 3: I took model 2 above and fixed a parameter to the estimated value in model 2, it resulted in df, AIC= 3, 2126.
My question is – how to select the best fitting model from the above candidate models? Can I simply use AIC (lower is better) and therefore select model 3?