Another operationalization for the mental model behind this post: let’s assume we have two people, Zero-Zoe and Nonzero-Nadia. They are employed by two big sports clubs and are responsible for the living and training conditions of the athletes. Zero-Zoe strictly follows study results that had significant results (and no failed replications) in her decisions. Nonzero-Nadia lets herself be informed by studies in a similar manner, but also takes priors into account for decisions that have little scientific backing, following a “causality is everywhere and effects are (almost) never truly 0” world view, and goes for many speculative but cheap interventions, that are (if indeed non-zero) more likely to be beneficial rather than detrimental.
One view is that Nonzero-Nadia is wasting her time and focuses on too many inconsequential considerations, so will overall do a worse job than Zero-Zoe as she’s distracted from where the real benefits can be found.
Another view, and the one I find more likely, is that Nonzero-Nadia can overall achieve better results (in expectation), because she too will follow the most important scientific findings, but on top of that will apply all kinds of small positive effects that Zero-Zoe is missing out on.
(A third view would of course be “it doesn’t make any difference at all and they will achieve completely identical results in expectation”, but come on, even an “a non-negligible subset of effect sizes is indeed 0″-person would not make that prediction, right?)
Thanks for the example! It reminds me of how I once was a very active Duolingo user, but then they published some update that changed the color scheme. Suddenly the duolingo interface was brighter and lower contrast, which just gave me a headache. At that point I basically instantly stopped using the app, as I found no setting to change it back to higher contrast. It’s not quite the same of course, but probably also something that would be surprising to some product designers—“if people want to learn a language, surely something so banal as a brightening up the font color a bit would not make them stop using our app”.