Evidence
EntityDraftv1.0.0-rc.2
Evidence: one observation, measured or calculated: what was observed, of which record, by which instrument or algorithm, over which interval, and the result. As in ISO 19156 (Observations and measurements).
https://opendevelopmentstandards.org/schema/1.0.0-rc.2/core/Evidence.json
Fields
Every entity also has the fields of the Entity base. The first row lists them.
From the Entity baseidnamedescriptionidentifierslinkscreatedAtupdatedAt
idRequiredtextnot emptyThe record's id: unique within the document. Fields that point at the record hold this id.
nametextThe name people use for the record.
descriptiontextWhat the record is, in words.
identifiersList ofDatatypeIdentifierIds the record has in other systems.
linksList ofDatatypeLinkOpen-ended links to other records.
createdAtdate-time (RFC 3339)When the record was created, in its producer's system.
updatedAtdate-time (RFC 3339)When the record last changed, in its producer's system.
typeOne ofthe codes belowHow the evidence was made.
measurement- Measured with an instrument.
calculation- Worked out by an algorithm.
estimate- Judged by a person or taken from a similar case.
document- Taken from a document, such as a data sheet.
observation- Seen or heard by a person, such as a site visit note or a photo.
validation- Shows that an algorithm version does what it claims, such as a conformance report.
subjectId ofany recordThe id of the record observed, such as a feature, a source or a run.
observedCode fromcore/quantities or acoustics/quantitiesWhat was observed, as a code from a quantities vocabulary.
resultThe result.
intervalWhen the observation was made.
locationWhere the observation was made.
pathinstrumentThe instrument that measured.
algorithmThe algorithm that calculated, or that validation evidence is about.
versiontextFor validation evidence: the algorithm version it validates. A reader treats it as stale for other versions.
traceThe run that made the result.
filesstateThe operating state the source was in.
conditionsList ofId ofConditionThe conditions during the observation, such as the weather.
originWhere the data came from, when not from this document's instruments or runs.
Links
Holds Parts this record embeds, with the field that holds each.
Points at Records whose ids this record holds, with the field that holds each.
- InstrumentEntityinstrumentA device that measures, such as a sound level meter, a microphone or a weather station, with its calibrations.
- AlgorithmEntityalgorithmA published or versioned computation, such as ISO 9613-2:2024, or a model trained on data. Sealed steps and runs refer to it by id, as the method they claim to follow.
- TraceEntitytraceWhat one run of a flow or an algorithm did: what it used, each step, what it made, and the verdict. Its terms follow W3C PROV where they map: agents (prov:wasAssociatedWith), inputs (prov:used), outputs (prov:generated).
- FileEntityfilesA file that records point at, such as a recording, a certificate, a photo or a grid, with its media type, its place and its hash. A file does not change: a changed file is a new File.
- Operating statePartstateA named way that a source runs, set by its operating properties, such as speed, load, flow rate or mode. Off is an operating state. Each emission names the state it holds for.
- ConditionEntityconditionsA state of the surroundings over an area and a time, such as the ambient sound, the terrain, the weather or the water. Its properties come from a quantities vocabulary; which list holds it (ambient, terrain, weather or hydrology) says what sort it is.
Held by Records that embed this one, with their field that holds it.
Pointed at by Records that hold this one's id, with their field that holds it.
- AlgorithmEntityvalidationsA published or versioned computation, such as ISO 9613-2:2024, or a model trained on data. Sealed steps and runs refer to it by id, as the method they claim to follow.
- AssessmentEntityevidenceAn evaluation of a development and its result, such as a noise impact assessment. It names its authors, scope and framework, the traces and evidence it rests on, and its conclusions. A trace is one run; an assessment can rest on many.
- ComparisonPartresultbenchmarkTwo results for the same thing, their difference, the tolerance that judges it and the verdict. Validation runs, monitoring against prediction and conformance tests use it.
- ConditionEntityevidenceA state of the surroundings over an area and a time, such as the ambient sound, the terrain, the weather or the water. Its properties come from a quantities vocabulary; which list holds it (ambient, terrain, weather or hydrology) says what sort it is.
- EmissionPartevidenceWhat a source gives off in one operating state, such as sound power, a pollutant rate or a discharge. A module schema can require more of it for its domain.
- PositioningDatatypeevidenceHow a position was obtained and how accurate it is. It holds the method, the time, the accuracy in metres and what the position rests on. The accuracy is absolute positional accuracy, as in ISO 19157.
Examples
An id that another example defines opens that record.
Full example
{
"id": "evidence-night-survey",
"name": "Night survey at the dwelling",
"type": "measurement",
"subject": "feature-dwelling",
"observed": "a_weighted_sound_pressure_level",
"result": {
"amount": 37.8,
"unit": "dB",
"statistic": {
"type": "energy_mean"
},
"averaging": "PT9H"
},
"interval": {
"start": "2026-07-14T22:00:00-06:00",
"end": "2026-07-15T07:00:00-06:00"
},
"instrument": "instrument-slm",
"state": "state-loaded",
"conditions": [
"weather-2026-07-14T22"
],
"links": [
{
"type": "reference",
"target": "file-recording-1",
"targetType": "File",
"role": "recording"
}
]
}Show 1 more exampleHide the other example
Minimal example: the required fields only
{
"id": "evidence-1"
}Changes and file
Changes
- 0.1.0 First version.
Schema file
Show the JSON SchemaHide the JSON Schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://opendevelopmentstandards.org/schema/1.0.0-rc.2/core/Evidence.json",
"title": "Evidence",
"description": "Evidence: one observation, measured or calculated: what was observed, of which record, by which instrument or algorithm, over which interval, and the result. As in ISO 19156 (Observations and measurements).",
"$ref": "Entity.json",
"type": "object",
"properties": {
"type": {
"type": "string",
"enum": [
"measurement",
"calculation",
"estimate",
"document",
"observation",
"validation"
],
"description": "How the evidence was made.",
"x-ods-options": [
{
"value": "measurement",
"title": "Measurement",
"description": "Measured with an instrument."
},
{
"value": "calculation",
"title": "Calculation",
"description": "Worked out by an algorithm."
},
{
"value": "estimate",
"title": "Estimate",
"description": "Judged by a person or taken from a similar case."
},
{
"value": "document",
"title": "Document",
"description": "Taken from a document, such as a data sheet."
},
{
"value": "observation",
"title": "Observation",
"description": "Seen or heard by a person, such as a site visit note or a photo."
},
{
"value": "validation",
"title": "Validation",
"description": "Shows that an algorithm version does what it claims, such as a conformance report."
}
]
},
"subject": {
"type": "string",
"description": "The id of the record observed, such as a feature, a source or a run.",
"minLength": 1,
"x-ods-ref": "*"
},
"observed": {
"type": "string",
"pattern": "^[a-z0-9]+(_[a-z0-9]+)*(\\.[a-z0-9]+(_[a-z0-9]+)*)*$",
"x-ods-vocabulary": "*/quantities",
"description": "What was observed, as a code from a quantities vocabulary."
},
"result": {
"$ref": "Value.json",
"description": "The result."
},
"interval": {
"$ref": "Interval.json",
"description": "When the observation was made."
},
"location": {
"$ref": "Location.json",
"description": "Where the observation was made."
},
"path": {
"$ref": "Path.json",
"description": "The path the result is for, such as one sound path from a source to a receptor."
},
"instrument": {
"type": "string",
"minLength": 1,
"x-ods-ref": "Instrument",
"description": "The instrument that measured."
},
"algorithm": {
"type": "string",
"minLength": 1,
"x-ods-ref": "Algorithm",
"description": "The algorithm that calculated, or that validation evidence is about."
},
"version": {
"type": "string",
"description": "For validation evidence: the algorithm version it validates. A reader treats it as stale for other versions."
},
"trace": {
"type": "string",
"minLength": 1,
"x-ods-ref": "Trace",
"description": "The run that made the result."
},
"files": {
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"x-ods-ref": "File"
},
"description": "The files that hold the evidence, such as a conformance report, a certificate or a signed assessment. A file outside the package gives its `url` and its hash."
},
"state": {
"type": "string",
"minLength": 1,
"x-ods-ref": "OperatingState",
"description": "The operating state the source was in."
},
"conditions": {
"type": "array",
"items": {
"type": "string",
"minLength": 1,
"x-ods-ref": "Condition"
},
"description": "The conditions during the observation, such as the weather."
},
"origin": {
"$ref": "Origin.json",
"description": "Where the data came from, when not from this document's instruments or runs."
}
},
"patternProperties": {
"^x-": {}
},
"unevaluatedProperties": false,
"examples": [
{
"id": "evidence-1"
},
{
"id": "evidence-night-survey",
"name": "Night survey at the dwelling",
"type": "measurement",
"subject": "feature-dwelling",
"observed": "a_weighted_sound_pressure_level",
"result": {
"amount": 37.8,
"unit": "dB",
"statistic": {
"type": "energy_mean"
},
"averaging": "PT9H"
},
"interval": {
"start": "2026-07-14T22:00:00-06:00",
"end": "2026-07-15T07:00:00-06:00"
},
"instrument": "instrument-slm",
"state": "state-loaded",
"conditions": [
"weather-2026-07-14T22"
],
"links": [
{
"type": "reference",
"target": "file-recording-1",
"targetType": "File",
"role": "recording"
}
]
}
],
"x-ods-status": "draft",
"x-ods-kind": "entity",
"x-ods-module": "core",
"x-ods-changes": {
"0.1.0": "First version."
}
}