Some evidence is rock solid. Some is a well-informed hunch. A score that treats them the same is overclaiming, and a diagnostic cannot afford that. Confidence tiers are how Pixie stays honest about it.
Every benchmark behind your Scaleup Score rests on evidence, and Pixie grades that evidence into one of three tiers. The tier sets how much weight the benchmark carries in your score.
Tier 1 (Authoritative) is the highest: regulatory or government-verified data, or strong empirical evidence from five or more peer-reviewed sources. It carries full weight. Tier 2 (Empirical) is evidence verified by three or more independent sources, and carries reduced weight. Tier 3 (Directional) rests on limited sources and is treated as indicative, so it carries the lowest weight.
The tiers describe the strength of the evidence behind a benchmark. They are not a percentage, and they do not measure how complete your own data is.
Tiers keep Pixie honest about how much it can stand behind, and give you a fair basis for judging how hard to lean on any one benchmark. Confidence tiers are included on both Pixie Score and Pixie Pro.