What is proof strength?
Proof strength is a measure of how much underlying evidence supports a signal. A product with many recent purchases produces a stronger purchase signal than one sitting at the minimum needed to qualify. It is the difference between “just enough” and “overwhelming”.
How is proof strength different from a threshold?
A threshold is a pass/fail floor — does the signal have the minimum evidence to qualify at all? Proof strength is the degree above that floor — how far past the minimum the evidence goes. Two products can both clear the same threshold while having very different proof strength.
How does proof strength feed the message score?
It is one of the components the score combines. A stronger-supported signal scores higher, all else equal, so among several qualifying candidates the engine favours the one with the most evidence behind it. Proof strength is what lets “strongly true” outrank “barely true”.
How is proof strength different from confidence?
Proof strength is how much evidence there is; confidence is how reliable that evidence is. A signal can be strong but drawn from a noisy sample, or modest but very reliable. The score uses both, because volume and reliability are different questions.
See the engine in action
The engine measures how much evidence sits behind each signal and favours the strongest.