When to trust the experts? Follow these guidelines to evaluate science on any topic

When faced with scientific claims about diet, supplements, teaching methods, or management practices, it is crucial to evaluate the strength of the evidence. Initial studies may appear convincing, but they may later be proven wrong. Scientists understand this self-correcting process, yet the public often treats early results as definitive.

The authors of a new study argue that this tendency to trust preliminary findings without considering their maturity leads to overconfident policy decisions and erodes trust in science. To distinguish between different levels of evidence, they propose the PERLS framework (Policy Evidence Readiness Levels). This framework classifies evidence based on how much scrutiny it has undergone.

When making decisions about trust and actions based on scientific claims, it is essential to ask whether the claim is supported by a single study, a few studies, or an accumulation of research. Claims backed by a single study or a small number of studies should be viewed as possibilities, not proven facts. While some preliminary results may hold up, many fail to replicate at larger scales.

However, acting on available evidence is not always avoidable, such as when facing a health crisis or market shift. The key is to remain flexible and adjust trust levels based on the strength of the evidence.