Event Grain

An event grain is the grain an event is recorded at: what one occurrence of the event is one of. It fixes whether the fact can be resolved to a single person, and if it cannot, what stands in the way, because a count of events is a count of people only when each event is one person's.

Its event grains— 4

• PersonOne event is one person's, and the brand can resolve it to that person: a visit, an open, a submission, a purchase, or a fact recorded about one known relationship.
• WithheldOne event is one person's act, but the platform that saw it holds the identity and releases only the aggregate, so the person is real and unresolvable from here.
• PlacementOne event is a delivery with no person in it: a placement, a drop, an airing. It says the message went out, and nothing about who received it.
• PublicOne event is an utterance in public, made by someone the brand has not resolved to a known person, so it is evidence about the brand and not about a relationship.

Why it matters

What goes wrong without it, as the commitments that license this kind say it, each standing on its sources.

• Separate executable actions, observed events and consumer actor grainWhat a system did and what a person did are different facts, and the two are easily merged — which is why event models separate what was explicitly triggered from what was implicitly observed. A send is not an open; a delivery total is not a set of people. Once an execution record and a behavioural observation are the same kind of thing, every count downstream quietly mixes them, and an audience figure stops being checkable.
  XDM ExperienceEvent Class · Declaring the Grain