what is a model selection algorithm how to specify interaction of model in r how many degrees of freedom are required to fit gam model? which metric is best for the selection of interactions? why is the degree of freedom for interactions different how many degrees of freedom can a semi parametric model have for each interaction? why are interactions selected which method is best for selecting interactions? k is the number of knots in a model of interaction what is the best model selection algorithm how many degrees of freedom can interact with different interactions in a semiparametric model? what is df for interactions on gam how does an interaction selector work? why do you use gam what is relationship between degrees of freedom and gam interaction? which model selection algorithm would be best for a subset of interaction data? can gam be penalized which is the best method to specify interactions without many degrees of freedom? how to select interaction using gam which of the following methods is best for modeling interaction? unpenalized? unpenalized