#48 - Good Medicine Starts With Saying I Don’t Know

What if the most dangerous AI answer is the one that sounds the most certain? We start with a playful challenge about the moon’s diameter, then use it to explore a much bigger question in healthcare: how should AI systems communicate uncertainty instead of simply projecting confidence to the user?We dive into how clinicians make decisions when the facts are incomplete. In the emergency department, documentation workflows, and automated ICD-10 coding, medical reasoning rarely depends on a single perfect answer. Clinicians rank a differential, search for evidence that could prove them wrong, prioritize what is urgent, and bring in specialists when needed. That process is built for uncertainty. Yet many healthcare AI tools, from large language models to traditional machine learning classifiers, are still designed to deliver one “best” answer, even when the situation calls for caution.The episode breaks uncertainty into two practical categories: aleatoric uncertainty, which comes from ambiguity and noise in the data, and epistemic uncertainty, which appears when a case falls outside the model’s knowledge. Along the way, we unpack what probability scores really mean, why near-ties deserve attention, and why out-of-distribution detection matters when a model might confidently mistake the unfamiliar for the known. The key takeaway is simple: safer AI systems do not hide uncertainty. They make it visible, communicate it clearly, and know when to abstain.References:Uncertainty-aware abstention in medical diagnosis based on medical textsVazhentsev et al.Nature Artificial Intelligence (2026)Credits:Theme music: Nowhere Land, Kevin MacLeod (incompetech.com)Licensed under Creative Commons: By Attribution 4.0https://creativecommons.org/licenses/by/4.0/