HI = E × P × C

HI  =  E  ×  P  ×  C

E = experience that happened to a person
P = said in public, left in a trail
C = contested (voted, replied, corrected)

Three factors, all required, because the product is zero if any one of them is zero.

E, experience. Something happened to a person. They took the flight, ran the firmware update, ate at the place, got the side effect. Not read about it. Not summarized it. It happened to them, and they remember it with the details that only show up when you were there: the queue was outside, the update bricked the second unit, the fries were fine but the burger was not.

P, public. They said it somewhere that leaves a trail. A comment with a timestamp, under a handle, in a thread other people can find. Private knowledge is still knowledge, but it is not HI in the sense this site means, because nobody else can reach it, cite it, or check it.

C, contested. Somebody could push back, and often did. Votes, replies, corrections, "that was fixed in 2.1", "not my experience at all". An unchallenged claim is a press release. A challenged claim that survived is evidence.

Why the multiplication matters:

• A private memory: E high, P = 0. Product is zero. Not HI.
• A confident blog post nobody can reply to: E maybe, P yes, C = 0. Not HI.
• A model answer: fluent, public, even contested, but E = 0. Nothing happened to it. Not HI.

The formula is not meant to be measured. It is meant to be argued with, which is itself C.