The specification
Free foreverIn short: the specification is the rulebook for a complete eDNA record, defining what must be written down about how a result was produced. Any laboratory can follow it, and anyone can check a record against it.
Formerly published at /standard. We renamed it, because a specification is what it is.
Common Measure publishes an open specification for expressing environmental DNA results so they can be compared across laboratories, methods and years. It is deliberately narrow. It adopts published standards where they exist and specifies only the parts that no standards body has yet addressed.
- Status
- In development
- Version
- v0.1 draft
- License
- CC BY 4.0
LAUNCH SCOPE
What the specification covers at launch
At launch in 2027, the specification covers DNA metabarcoding of submitted sequence data, with dedicated pipelines for CO1, 12S, 16S (bacteria and vertebrates), fungal ITS and plant ITS. Other amplicons run through a general pipeline.
Baetis tricaudatus is one of the most common stream mayflies in the United States. Barcode studies have found COI divergence above 20% among specimens given that name, yet a single California watershed holds just one lineage. The name alone cannot tell you which you have. A record keyed to the sequence can.
Stauffer-Olsen et al. 2017, Freshwater Science. doi:10.1086/69197300 · RELATIONSHIP TO PUBLISHED STANDARDS
What this specification does not duplicate
Where an international or national standard already specifies something, we adopt it by reference rather than restating it. This specification is scoped to what remains unspecified.
| Area | Governed by | Our position |
|---|---|---|
| Water sampling, filtration and preservation | ISO 17805:2026 | Adopted by reference. Our assurance record fields for collection and preservation follow it |
| Extraction from filters | ISO/AWI 26488, in development | We will adopt it on publication |
| Reporting requirements and terminology | CSA W214:21, Environmental DNA (eDNA) reporting requirements and terminology, a published National Standard of Canada | We will align our vocabulary and reporting fields to it |
| Laboratory competence | ISO/IEC 17025 | Outside our scope entirely. Accreditation is a matter for accreditation bodies |
| Publishing to biodiversity databases | Darwin Core, MIxS, and the requirements of each database | We map to them rather than defining our own. See the crosswalk |
| Sequence identity across runs, laboratories and years | Not currently specified | This specification |
| Reference database version control | Not currently specified | This specification |
| Measured agreement between laboratories | Not currently specified | This specification, informed by the cross-laboratory study |
| Where data is stored and processed | Contract and jurisdiction, not specification | Stated openly on Who We Are and in the FAQ |
Common Measure is not accredited by, endorsed by, or affiliated with ISO, CSA Group, or any standards body. Adopting a published standard by reference is something anyone may do. We say which standards we follow so that a reader can check.
01 · SCOPE
What our specification covers
The specification has five components. They are being developed in the order below, because each depends on the one before it.
- 01
The identifier
Rules for assigning a permanent identifier to a sequence, and for resolving that identifier when the same sequence is encountered again in a different run, laboratory or year. Covers assignment, resolution, merging and retirement.
In development
- 02
The reference frame
Which reference databases are consulted, in what order, at which versions, and how conflicting assignments are resolved. Includes the taxonomic authority used and how names are attached to identifiers as versioned annotations rather than as the record itself.
In development
- 03
The assurance record
The metadata that must accompany a result for it to be considered conformant: molecule type and marker, collection time and preservation, filter type, replicate structure, assay coverage, control results, thresholds applied, and pipeline and reference database versions. Planned: bait panel identity and version (hybridization capture).
Version 0.1 of the assurance record specifies fields for metabarcoding. Fields for targeted assays, capture and environmental RNA are drafted but not yet published, because we would rather publish them after testing than before.
Draft
- 04
Conformance
What it means for a result, a laboratory or a dataset to be conformant, and what a conformance claim entitles the holder to say. Without this, "conformant" means whatever the person using the word wants it to mean.
- 05
The vocabulary
The controlled set of terms the specification uses, maintained separately and versioned independently.
v1.0 publishedRead the vocabulary →
02 · BOUNDARIES
What our specification does not do
Specifications fail more often from creeping past their remit than from being too narrow. These are outside scope, permanently:
It does not prescribe field methods.
How you sample is your business and your regulator's. Our specification governs how a result is expressed, not how it was obtained.
It does not certify laboratories.
Conformance is a property of a result and its accompanying record, not an accreditation of the organization that produced it.
It does not interpret ecology.
Our specification makes results comparable. What they mean is a question for the people who know the system.
It does not replace regulatory method approval.
Where an agency has an approved method, our specification describes how to express its output — it does not substitute for it.
03 · VERSIONING
How versions work
A specification that changes silently is worse than no specification, because results produced under different rules become indistinguishable.
- 01
Versions follow major.minor.patch. A major version indicates a change that can alter how existing data is interpreted. A minor version adds capability without changing existing interpretation. A patch corrects errors and wording.
- 02
Every published version remains available permanently at a stable URL. Superseded versions are marked as superseded, never removed.
- 03
Every result expressed under our specification records the version it was produced under. A result cannot be silently reinterpreted by a later version.
- 04
Changes that can alter interpretation go out for public comment before they take effect. Comments and their outcomes are published.
04 · TERMS OF USE
How you may use it
License
The specification, the vocabulary and all validation data are published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may use, adapt, redistribute and build commercial products on them, including in competition with us, provided attribution is retained.
There is no fee and no license to negotiate. Free. At launch, it will require an email-verified account. If we ever put the specification behind a payment, we have stopped publishing open infrastructure.
CC BY 4.0 license terms →How to cite
Common Measure. (2026). Common Measure Environmental DNA Data Specification, version 0.1 draft. Washington, DC. https://commonmeasure.bio/specification
A persistent identifier will be assigned on first stable release. Until then, cite the version and the access date.
05 · STATUS
Where each part stands
| Component | Status | Version | Next milestone |
|---|---|---|---|
| Vocabulary | Published | 1.0 | Passes to the science committee on formation |
| Assurance record | Draft | 0.1 | Field-tested through the cross-laboratory study |
| Identifier | In development | — | Draft for comment, 2027 |
| Reference frame | In development | — | Draft for comment, 2027 |
| Conformance | Planned | — | Follows the identifier and reference frame |
The cross-laboratory comparison study is the mechanism by which the assurance record moves from draft to tested. Until a result exists showing what a shared reference frame is actually worth, the specification is a proposal rather than a standard, and we would rather say so.
This is being built in the open
A specification nobody helped shape is a specification nobody adopts. If you run a laboratory, operate a monitoring program, or maintain a database that environmental DNA results have to reach, we would like your objections early rather than your compliance late.
