Glossary

Open data standards

A data standard is an agreed specification for describing and structuring data so it can be shared and reused. An open data standard is published under a license that lets anyone use it freely. Standards generally fall into three overlapping kinds:

Schematic

Defines the structure of data — fields, types, and how records fit together (e.g. GTFS).

Semantic

Defines shared meaning and vocabularies so values are interpreted consistently (e.g. NIBRS).

Atomic

Defines the smallest agreed units of representation, such as codes for dates, currencies, or coordinates (e.g. ISO 8601, WGS84).

An example: GTFS

The General Transit Feed Specification defines how a transit agency publishes routes, stops, and schedules. Because agencies worldwide use the same format, one app can plan trips in hundreds of cities — a concrete illustration of what a shared, open standard makes possible.

Assessment metrics

Each standard is assessed against nine metrics, shown as color-coded icons:

• Open License

  The standard is published under an open license that permits free reuse.

• Transferable to Other Jurisdictions

  The standard can be adopted by jurisdictions beyond the one that created it.

• Stakeholder Participation

  Stakeholders and the public were able to participate in developing the standard.

• Consensus-Based Governance

  The standard is governed by consensus among its contributors.

• Extensions

  The standard supports extensions or profiles for local needs.

• Human Readable

  Data expressed in the standard is understandable by a person, not only a machine.

• Machine Readable

  Data expressed in the standard is structured for automated processing.

• Requires Up-To-Date / Real-Time Data

  The standard depends on frequently updated or real-time data.

• Metadata

  The standard defines or requires metadata about the data it describes.

Color key

• Yes — the standard meets this criterion
• No — it does not
• No data — not assessed or unknown

Categories

Standards are organized into categories and subcategories describing the domain of municipal data they serve. Browse them on the categories page. The category framework builds on foundational open-data research for the directory.