why use a nested model which criteria must be applied to fit the new model? why is a model not fitted on the same data set? why are the nested models used criteria nested model why two models of metabolite can't be fitted in the same dataset what is the criteria for model selection of a nested model? why a model needs to have only 6 observables which data set is the nested model fit on what is model selection criteria what is the criteria for model selection why would a nested model be useful? criteria for nested model selection criteria for nested modeling what criterion is used to select a model? which of the following is a criteria used to select the best model for nested data? what is a nested model why use aic criteria what is criteria for selection why are nested models not fitting