Commitment · Structural

A reading names its unit, and the unit fits its form

adopted a build gate proves it

Every Metric is measured in exactly one Unit from a governed vocabulary: Count, Percent, Ratio, Currency, Rank and Score. A Unit declares which arithmetic forms it fits, and the build refuses a KPI whose form its Metric's unit does not fit, a quotient measured in a count, and a Metric in Percent or Ratio that names its numerator directly but no denominator. The unit belongs to the Metric, because the calculation carries it and the KPI only reads it.

What goes wrong without it

A number without its unit is not a reading. Metrology defines a quantity value as a number and a reference together, and the unit codes exist because a value that travels without its unit is misread at the far end: a rate and a count that print the same figure have said different things, and percent is a name for the number 0.01, not a kind of thing. This model already fixed a KPI's direction and form as facts in the graph; the unit is the third fact of that family. Declaring which forms a unit fits is what a unit ontology does when it binds units to kinds of quantity, and it turns unit-form agreement from a review into a check.

What proves it — 1

Each is a gate the build runs: a check inside a ring, a whole ring, or an eval beside them. A build stops at the first that refuses.

registry integrityunit agreement
Every Metric is measured in one Unit that fits every arithmetic form the KPIs reading it take; a quotient is never measured in a count; and a reading in percent or as a ratio that names its numerator directly names a denominator, so a number and its unit leave here together and a share always says what it is a share of.

Derived from — 5

BIPM, Joint Committee for Guides in MetrologyInternational Vocabulary of Metrology: Basic and General Concepts and Associated Terms (VIM), JCGM 200:2012
International Organization for StandardizationISO 80000-1:2022 Quantities and units, Part 1: General
Regenstrief Institute and the UCUM Organization, 2024The Unified Code for Units of Measure, version 2.2
QUDT.orgQUDT Ontologies: Quantities, Units, Dimensions and Data Types, release 2.1
International Organization for Standardization, maintained by SIXISO 4217 Currency codes

Kinds it licenses

Metrics KPIs Units Measure Form

Relationships it licenses

measured in · fits form · reads as · has metric

Where this model stands

Every Metric is measured in one Unit. Most read in Percent; the rest are counts, currency amounts, three ratios, one rank and one score.

Count, Percent and Ratio are the units the check reasons about by name: a quotient is never measured in Count, and a Metric measured in Percent or Ratio that names its numerator directly also names a denominator.

Return on Ad Spend is a Ratio and not a Percent, because the trade reads it as a multiple; Cost per Lead and Revenue per Lead are Currency, because the number prints as money and the per-lead is the form; Frequency is a Ratio of deliveries to people; Position is a Rank, an ordinal with an order and no arithmetic; Page Experience Index is a Score built against thresholds.

Currency is one unit here, not one unit per currency: the three-letter code and the rate date are facts about a published reading, not about the Metric.

A Metric that computes from a Formula, or that has no source yet, is measured in its unit like any other, but the denominator law does not reach it: a Formula names its inputs without roles, and a Metric with no inputs has nothing to check.

What it does not claim

No Metric reads in time, so no unit of duration is declared; the first Metric that does adds it.

Currency conversion and the rate date live with a published reading, not with the Metric; a measurement contract that publishes money across currencies adds them.

RUL-027