The signals · The signal set · Element

The freshness

How current the signal is.

The part

What it is

Behaviour from two years ago describes a former customer. Stale signals produce confidently wrong personalisation, which is the worst kind.

A decay rule — signals older than a period stop counting — is simple and effective.

The smallest level

The attributes it carries

Each attribute is one of the framework’s shared types. What a date is, and how it is written, is defined once for the whole model — the note here says what it means in this particular place.