CENSO
An ontology for censored environmental observations · version 2.4.0
https://w3id.org/censo/
What it is
CENSO extends SOSA/SSN for measurements produced by a method that has a limit of detection. Its modelling commitment is that the limit is carried onto the result. SSN-System binds a detection limit to a sensor; CHMO, the closest prior art, binds it to the method, as a figure of merit of an assay. Neither can say that a particular measurement fell below it — and “censored” is a property of a result, not of the procedure that produced it.
Because the limit reaches the result, a non-detection is typed as the interval [0, LOQ] it actually establishes rather than stored as a zero, and compliance is three-valued: compliant, exceeding, or not determinable — with the third subtyped by the reason it could not be decided.
The third outcome is not a convenience:
Where a result is referred to as “less than limit of quantification”, and the limit of quantification of that technique is above the EQS, the result for the substance being measured shall not be considered for the purposes of assessing the overall chemical status of that water body.
— Directive 2008/105/EC, Article 3(3b)
That outcome is neither compliant nor exceeding. A two-valued data model cannot express it, so compliance with the provision cannot be audited.
Resolvable IRIs
| IRI | Resolves to |
|---|---|
| https://w3id.org/censo/ | the vocabulary — Turtle, RDF/XML or JSON-LD by content negotiation |
| https://w3id.org/censo/2.4.0 | this release specifically |
| https://w3id.org/censo/1.0.0 | the 1.0.0 release, unchanged since it was published |
| https://w3id.org/censo/2.0.0 | the 2.0.0 release, unchanged since it was published |
| https://w3id.org/censo/2.1.0 | the 2.1.0 release, unchanged since it was published |
| https://w3id.org/censo/2.2.0 | the 2.2.0 release, unchanged since it was published |
| https://w3id.org/censo/2.3.0 | the 2.3.0 release, unchanged since it was published |
| https://w3id.org/censo/reg/ | the regulation-package vocabulary |
| https://w3id.org/censo/reg/eu-2008-105-2026 | Directive 2008/105/EC, Annex I, consolidated text in force 10 May 2026 — 111 thresholds |
| https://w3id.org/censo/reg/tr-ysky-2016 | Turkish Surface Water Quality Regulation, Table 4 (2016) — 434 thresholds |
| https://w3id.org/censo/shapes | SHACL shapes for validation and materialisation |
| https://w3id.org/censo/alignment | correspondences to ChEBI and CHMO; not imported by the vocabulary, so its commitments are taken only when the module is loaded explicitly |
| https://w3id.org/censo/shapes/2.4.0 | this shapes release specifically |
| https://w3id.org/censo/shapes/1.0.0 | the 1.0.0 shapes release, unchanged since it was published |
| https://w3id.org/censo/shapes/2.0.0 | the 2.0.0 shapes release, unchanged since it was published |
| https://w3id.org/censo/shapes/2.1.0 | the 2.1.0 shapes release, unchanged since it was published |
| https://w3id.org/censo/reg/2.4.0 | this regulation vocabulary release specifically |
| https://w3id.org/censo/reg/1.0.0 | the 1.0.0 regulation vocabulary release, unchanged since it was published |
| https://w3id.org/censo/reg/2.0.0 | the 2.0.0 regulation vocabulary release, unchanged since it was published |
| https://w3id.org/censo/reg/2.1.0 | the 2.1.0 regulation vocabulary release, unchanged since it was published |
| https://w3id.org/censo/alignment/2.0.0 | this alignment release specifically |
| https://w3id.org/censo/alignment/1.0.0 | the 1.0.0 alignment release, unchanged since it was published |
Regulation packages contribute individuals only — no class, no property — which is what makes one safe to load in place of, or alongside, another.
Files
| File | Format |
|---|---|
censo-full.ttl | Turtle |
censo-full.owl | RDF/XML |
censo-full.jsonld | JSON-LD |
censo-regulation.ttl | regulation vocabulary |
censo-shapes.ttl | SHACL |
censo-alignment.ttl | external alignment |
reg/eu-2008-105-2026.ttl | Directive 2008/105/EC, Annex I, consolidated text in force 10 May 2026 |
reg/tr-ysky-2016.ttl | Turkish Surface Water Quality Regulation, Table 4 (2016) |
Reuse
Released under CC BY 4.0. CENSO extends SOSA/SSN and reuses PROV-O, SKOS and QUDT rather than redefining their terms. Correspondences to external resources are asserted rather than absorbed: 285 rdfs:seeAlso pointers to ChEBI and CHMO are published in censo-alignment.ttl, a module the vocabulary does not owl:imports. The alignment is therefore optional, and the ontological commitments of the resources it references are not inherited by an application that loads the vocabulary alone.