John Carlin says, “‘Identifying variables that independently predict…’ is not a well-defined research task

John “Bayesian Data Analysis” Carlin writes: Recent developments in the methodology of epidemiological research have emphasized the importance of achieving clarity of purpose by classifying research questions into one of three types: descriptive, predictive, and causal. . . . I [Carlin] do not believe that studies aiming to “identify” independent predictors or “prognostic factors” are addressing well-defined research questions. Indeed, beyond the issues already raised, there is a broader question of the extent to which it is ever sensible to frame a research question as if it could be answered dichotomously, as in “is this an (independent) prognostic factor?” Prediction questions, which include prognosis, are those that involve the development of a model or algorithm to provide predictions of outcomes using available variables that are potential predictors. This all makes sense. I kinda think that descriptive, predictive, and causal are all the same thing–or, more precisely, that…