Core ontology
Four knowledge primitives — entity, relationship,
fact, rule — cover things, the links between them,
assertions about them, and the conditional statements that connect assertions.
Provenance
<aodm:source> records where a statement came from, with a URI,
a title, when you retrieved it, and separately when the source itself made the
claim.
Confidence
<aodm:confidence> carries a value from 0.0 to 1.0, optionally
tagged with the method that produced it, so uncertainty travels with the data
instead of being lost at the boundary.
Structured measurement
<aodm:value> expresses a quantity as a number with a unit and
an optional tolerance, or as a min/max range. Units follow UCUM codes. No
regex-parsing magnitudes out of prose.
Temporal validity
valid-from and valid-to bound when an assertion holds.
Superseded knowledge is excluded from current queries but retained for audit,
never silently deleted.
Polarity
polarity="negative" states that something is known to be false,
which is a different claim from having no information. Both the format and the
rules keep the two apart.
Derivation tracking
derived-from records which rule and which facts produced an inferred
statement, so you can answer “why is this believed?” and trace every
conclusion that rests on a given source.
Content hashing
Self-describing digests (sha256:…) let the same fact arriving
from two pipelines be recognised as one fact rather than ingested twice.
Dual serialisation
Every document can be written as XML or as JSON, with a field-for-field mapping between them. Both forms have a published, tested schema.
Documented validation rules
Referential integrity, cardinality, measurement, temporal and provenance rules that no schema language can express are specified separately, with two named conformance levels.
Online validator
Paste a document and check it against every rule in the specification, in the browser. Nothing is uploaded and nothing is stored.
HTML embedding profile
The v1.1 profile annotates existing pages in place via
xmlns:aodm, with no runtime dependency, and remains supported
alongside 1.2.
Element reference
| Element | Purpose | Key attributes |
|---|---|---|
entity |
A thing: object, concept, component, actor, place | id, type, label, hash |
relationship |
A directed, typed link between two entities | subject, predicate, object, polarity, valid-from, valid-to, derived-from |
fact |
An assertion, optionally scoped to an entity or relationship | about, polarity, valid-from, valid-to, hash, derived-from |
rule |
IF conditions THEN conclusion, by reference | id, valid-from, valid-to |
source |
Provenance for any of the above | uri, title, retrieved, asserted |
confidence |
How sure we are, 0.0–1.0 | value, method |
value |
A structured measurement on a fact | number, min, max, tolerance, unit |