How We Rate Evidence and Benefits

The A, B, and C labels describe how directly the evidence supports a claim; they do not describe how exciting the result sounds. Benefit size is a separate 1-to-3 label: 1 is small, 2 is moderate, and 3 is large within its own benefit category. A large money benefit is not automatically larger than a small health or freedom benefit.

Evidence grades

• A — direct, decisive support. For a rule or eligibility claim — what a program says, who qualifies, and a stated amount, threshold, or deadline — a current official source that explicitly gives that detail is enough for A. For an outcome claim — whether an action improves health, income, or long-term life — A requires a measured estimate from a meta-analysis, randomized trial, or large cohort. A current official source can establish what a rule says, but it does not turn an outcome claim into an A.
• B — useful research, limited measurement. There is relevant research or an official source, but the result is difficult to quantify, depends on circumstances, or has important limits.
• C — consensus or practical experience. The advice is supported by established professional consensus or practical experience, while a direct numerical estimate is not available or would overstate what is known.

An evidence grade is not a ranking of a person, agency, or source. It is our short description of the support for one specific claim, and a single entry can contain claims with different levels of certainty.

Benefit size and costs

Benefit size follows the entry's benefit kind — health, money, time, or freedom — and uses the same 1-to-3 scale within that kind. We do not convert a health benefit into dollars or add unlike outcomes together. Cost labels are also separate: money, time, and effort are shown independently so a reader can see what a choice asks of them.

We review the labels whenever the underlying claim changes and during the 90-day check for time-sensitive numbers. See the editorial policy for the verification process.