Individual response

[Pavlos_Msaouel]

@ESMD

I think this is really the crux of the issue. Some might argue that trying to find structure in randomness is to deny the very existence of randomness…Opinions about whether or not it’s futile to even try to find patterns in chaos seem (crudely) to delineate two ideologies- causal inference epidemiology and statistics.

This needs clarification: There are at least two major types of probabilities used in stochastic inference:

1. Aleatory probabilities that are connected to physical processes such as the random treatment allocation in randomized controlled trials (RCTs). This is randomness that is based on a well-defined physical process and its uncertainty can thus be validly quantified by standard statistical methodology.

2. Epistemic probabilities that express our ignorance.

The two can be numerically equivalent and considered to express “randomness”. But they are fundamentally different as nicely described, e.g., here.

Because frequentism focuses on aleatory probabilities whereas Bayes allows both, these considerations can degenerate into the endless frequentist vs Bayes debate that would be counterproductive in this thread. Whether using a Bayesian or frequentist lens, a major task for physician scientists is to convert epistemic probabilities into aleatory ones as much as possible, chiefly through experimental design along with careful observations such as correlative analyses of patient samples. These need to be embedded in statistical models informed by causal considerations.