Testing changes · The result · Element
The record
What is kept.
The part
What it is
All results including nulls, so that the programme’s actual win rate is known and so the same change is not retried.
A win rate around a quarter is normal and healthy; a reported rate near one indicates only obvious changes are being tested.
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.