Data format specifications (Gaia Guide)

Data format specifications

XML Specifications


This page lists the XML schemas that define the data formats underpinning this fieldguide. It is hoped that these formats or some variation of them will encourage broader sharing of data between fieldguide resources on the Internet.

All of the schemas on this website, except for the xml.xsd schema, are licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.

Each schema is intended to be self documenting, being a set of grammatical rules for the data formats and an explanation of how those formats are to be used. Thus, you can download the pages that explain the schemas, and the downloaded source for that page will be the schema itself.

Core XML Schemas.

Core field guide schema

The fieldguide schema describes an XML format for fieldguide data. Fieldguide data includes:

  • Descriptions of groups of specimens that share specific features (e.g. a species of bird or fish);
  • Hierarchical organisations of groups enabling users to drill down from general groupings to more specific ones; and
  • Data about specific identification events for individual specimens.

Each group is a unique identifier (a URI). That identifier is used in hierarchies to show relationships between groups. It is also used in descriptions to specify which group the description describes. It is also used in identifications to specify which group identification is recorded by the identification documentation.

A group will commonly be included in more than one hierarchy, giving multiple ways of drilling down from a general identification to a more precise one. A group will also potentially have more than one description, for example, a description in English and a description in French. Descriptions may also be created by multiple sources, leading to a proliferation of descriptions for the one group. Quite naturally, there will be more than one identification for each group as records of identification accumulate.

A description identifies the group that it describes using the ID of that group. It then associates that group with a set of characteristics, where each characteristic describes a feature that specimens in the group can be expected to have.

A core set of characteristics are defined in this fieldguide schema. These can be expected to be generally useful for most species. Where additional characteristics are required, to describe more specific groups of specimens, these can be defined in new schemas. The constraints on how those additional characteristics are defined are very weak. They simply need to be in the substitution group for the abstract characteristic element, defined in this schema.

In some cases, a characteristic is best described by a resource that is external to the description markup. For example, images are external binary files. An image characteristic is simply a reference to the ID associated with the external binary file, along with a caption explaining the nature of the image and a range of additional data documenting who contributed the image, as well as how that image is allowed to be reused. References to external websites and to academic papers are other examples of characteristics that define a connection to an external resource.

Literature references schema

This schema defines the markup to be used in references to authoritative literature.

XML namespace schema

This schema document describes the XML namespace, in a form suitable for import by other schema documents.

See and for information about this namespace.

Note that local names in this namespace are intended to be defined only by the World Wide Web Consortium or its subgroups. The names currently defined in this namespace are listed below. They should not be used with conflicting semantics by any Working Group, specification, or document instance.

See further below in this document for more information about how to refer to this schema document from your own XSD schema documents and about the namespace-versioning policy governing this schema document.

Extension XML Schemas for specialised description characteristics.

Characteristics of species that inhabit the marine environment

This schema defines characteristics that are useful in identifying groups of specimens that inhabit the marine environment. It extends the core fieldguide schema.

Characteristics of fish

This schema defines characteristics that are useful in identifying groups of fish. It extends the core fieldguide schema.

Characteristics of echinoderms

This schema defines characteristics that are useful in identifying marine echinoderms.

Characteristics of crinoids

This schema defines characteristics that are useful in identifying crinoids.

About species that inhabit the terrestrial environment

This schema defines characteristics that are useful in identifying species that inhabit the terrestrial environment.

About birds species

This schema defines characteristics that are useful in identifying bird species.

Supporting materials

This specification stylesheet (conforming to XSLT 1.0) transforms the original XML Schema into a human-readable HTML page explaining the use of the grammatical constructs in the schema itself.