Generic schema for an arbitrarily detailed description of "things"
STILL A DRAFT!!
This schema provides a generic Thing concept as a basic building block.
Key concepts of this schema are that any Thing
- has a unique identifier (
id) - can be further described by attributes (
has_attributes) and qualified relations to other "things" (is_characterized_by), without prescribing a particular vocabulary - can be associated with a specialized schema class for enabling detailed
validation and precise data transformations (
schema_type) without limiting the general expressiveness to a fixed set of classes available in any given (derived) schema.
More information on this schema is available on a dedicated page.
Each class comes with dedicated examples that exemplify its use. A good
starting point are the examples of the Thing class.
Although this generic schema could be used directly, it is meant to be used
as a foundational building block for more targeted schemas. Therefore, the
schema does not define common slots like name, or description, and leaves
this to more targeted schemas to decide if such slots are needed, and how they
should be defined. The envisioned use and reuse of this schema is to import
it and built targeted derivatives of Thing and other classes provided here.
See the PROV schema for an example that is built on this schema.
The schema definition is available as
Upcoming changes to this schema may be available in an (unreleased) development version.
URI: https://concepts.datalad.org/s/things/v1
Name: things-schema
Schema Diagram
erDiagram
ThingMixin {
uriorcurie schema_type
uriorcurie type
}
ValueSpecificationMixin {
uriorcurie range
string value
}
AttributeSpecification {
uriorcurie schema_type
uriorcurie type
uriorcurie range
string value
}
Property {
uriorcurie id
uriorcurie schema_type
uriorcurie type
}
Statement {
}
Thing {
uriorcurie id
uriorcurie schema_type
uriorcurie type
}
ValueSpecification {
uriorcurie range
string value
uriorcurie id
uriorcurie schema_type
uriorcurie type
}
ThingMixin ||--}o AttributeSpecification : "has_attributes"
ThingMixin ||--}o Statement : "is_characterized_by"
AttributeSpecification ||--|| Property : "predicate"
AttributeSpecification ||--}o AttributeSpecification : "has_attributes"
AttributeSpecification ||--}o Statement : "is_characterized_by"
Property ||--}o Thing : "relations"
Property ||--}o AttributeSpecification : "has_attributes"
Property ||--}o Statement : "is_characterized_by"
Statement ||--|| Thing : "object"
Statement ||--|| Property : "predicate"
Thing ||--}o Thing : "relations"
Thing ||--}o AttributeSpecification : "has_attributes"
Thing ||--}o Statement : "is_characterized_by"
ValueSpecification ||--}o Thing : "relations"
ValueSpecification ||--}o AttributeSpecification : "has_attributes"
ValueSpecification ||--}o Statement : "is_characterized_by"
Classes
| Class | Description |
|---|---|
| AttributeSpecification | An attribute is conceptually a thing, but it requires no dedicated identifier (id). Instead, it is linked to a Thing via its has_attributes slot and declares a predicate on the nature of the relationship. |
| Statement | An RDF statement that links a predicate (a Property) with an object (a Thing) to the subject to form a triple. A Statement is used to qualify a relation to a Thing referenced by its identifier. For specifying a qualified relation to an attribute that has no dedicated identifier, use an AttributeSpecification. |
| Thing | The most basic, identifiable item. In addition to the slots that are common between a Thing and an AttributeSpecification (see ThingMixin), two additional slots are provided. The id slot takes the required identifier for a Thing. The relation slot allows for the inline specification of other Thing instances. Such a relation is unqualified (and symmetric), and should be further characterized via a Statement (see is_characterized_by). From a schema perspective, the relation slots allows for building self-contained, structured documents (e.g., a JSON object) with arbitrarily complex information on a Thing. |
| Property | An RDF property, a Thing used to define a predicate, for example in a Statement. |
| ValueSpecification | A Thing that is a value of some kind. This class can be used to describe an outcome of a measurement, a factual value or constant, or other qualitative or quantitative information with an associated identifier. If no identifier is available, an AttributeSpecification can be used within the context of an associated Thing (has_attributes). |
| ThingMixin | Mix-in with the common interface of Thing and AttributeSpecification. This interface enables type specifications (rdf:type) for things and attributes. This is complemented by the schema_type slot (also rdf:type) that serves as a type designator for specialized schema classes, to enable targeted validation and data transformation. A thing or attribute can be further describe with statements on qualified relations to other things (is_characterized_by), or inline attributes (has_attributes). |
| ValueSpecificationMixin | Mix-in for a (structured) value specification. Two slots are provided to define a (literal) value (value) and its type (range). |
Slots
| Slot | Description |
|---|---|
| has_attributes | Declares a relation that associates a Thing (or another attribute) with an ... |
| id | Globally unique identifier of a metadata object, such as a Thing |
| is_characterized_by | Qualifies relationships between a subject Thing and an object Thing with ... |
| object | Reference to a Thing within a Statement |
| predicate | Reference to a Property within a Statement |
| range | Declares that the value of a Thing or AttributeSpecification are instance... |
| relations | Declares an unqualified relation of the subject Thing to another Thing |
| schema_type | Type designator of a schema element for validation and schema structure handl... |
| type | State that the subject is an instance of a particular RDF class |
| value | Value of a thing |
Enumerations
| Enumeration | Description |
|---|---|
Types
| Type | Description |
|---|---|
| Boolean | A binary (true or false) value |
| Curie | a compact URI |
| Date | a date (year, month and day) in an idealized calendar |
| DateOrDatetime | Either a date or a datetime |
| Datetime | The combination of a date and time |
| Decimal | A real number with arbitrary precision that conforms to the xsd:decimal speci... |
| Double | A real number that conforms to the xsd:double specification |
| Float | A real number that conforms to the xsd:float specification |
| Integer | An integer |
| Jsonpath | A string encoding a JSON Path |
| Jsonpointer | A string encoding a JSON Pointer |
| Ncname | Prefix part of CURIE |
| Nodeidentifier | A URI, CURIE or BNODE that represents a node in a model |
| Objectidentifier | A URI or CURIE that represents an object in the model |
| Sparqlpath | A string encoding a SPARQL Property Path |
| String | A character string |
| Time | A time object represents a (local) time of day, independent of any particular... |
| Uri | a complete URI |
| Uriorcurie | a URI or a CURIE |
Subsets
| Subset | Description |
|---|---|