The intuition behind projpred is amazing and the tutorials walkin through the steps are extremely informative. Thank you very much @avehtari @jpiironen
I had a question on including interaction terms and non - linear effects for continous predictors.
Interactions - If I have a priori reason to believe that two effects interact, should I include this in the calculation of tau? If these are categorical predictors, this would amount to the total number of parameters to estimate this interaction?
Non - linear - Non linearity of continous predictors is quite common esp in medical data and binning/dichotmizing often looses a lot of information. Instead, I’d like to model these as restricted cubic splines. I can’t say how many knots but typically suggested are 4 - 5. Would that mean, for each continous covariate I model as a restricted cubic spline, I would need to incorporate 4 for the calculation of tau? (assuming I have prior reason to believe that all the covariates I’m modeling as splines are related to the outcome).
Thank you and looking forward to hearing your insights on this!