In general, I'm wondering if there it is ever better not to use orthogonal polynomials when fitting a regression with higher order variables. In particular, I'm wondering with the use of R:
If poly()
with raw = FALSE
produces the same fitted values as poly()
with raw = TRUE
, and poly
with raw = FALSE
solves some of the problems associated with polynomial regressions, then should poly()
with raw = FALSE
always be used for fitting polynomial regressions? In what circumstances would it be better not to use poly()
?