Models

The LongSpine spine relies on the Linked Data technology stack (see Principles > Linked Data) for technical interoperability with lots of other Internet-based data and an overarching model (next section) for conceptual alignment. Additionally, all LongSpine Datasets use elements from a set of background models (below) which afford them conceptual alignment with many other datasets outside the spine itself, such as those published by the Australian Government Linked Data Working Group.

§ Modelling Paradigm

This project implemented a series of Semantic Web data models, all formulated according to the Web Ontology Language (OWL). This means data according to the models is presented in Resource Description (RDF) formats, can be stored in an RDF triplestore (a form of graph database), be queried using the SPARQL query language and can be joined to any other data that is also presented according to any of the very many OWL models in RDF.

OWL was chosen as the modelling system as there are very many public OWL models in wide use of relevance to this project's domain (e.g. the Organization Ontology) and OWL models are specialisable, extensible, technically interoperable (with any other OWL models) and data made according to them can be presented online as Linked Data allowing human- and machine-access across institutions.

§ Overarching Model

The structure of LongSpine's Dataset and Dataset relations (Linksets) (see Principles > Datasets and Linksets) adheres to the LocI ontology however the content of the Datasets does not, since LocI is about spatial objects and LongSpine is not. LongSpine content adheres to the very general LongSpine Ontology, an informal outline of which is given in Figure M1.


Figure M1: The LongSpine overarching model

The LongSpine ontology can be treated as the simples or fall-back data integrator: all data from all Datasets and Linksets, regardless of their specifics, can be viewed as LongSpine ontology data and used accordingly. The LongSpine Ontology documentation gives an example of specialised CRS Ontology data viewed as generic LongSpine ontology data.

§ Background Models

There are a series of well-known OWL models that are used for concepts relevant to LongSpine. These include both the technical, structural, models of how to represent data elements generally and also the conceptual models of particular domains' concepts. The following models, with notes on their role, are used by LongSpine:

Table M1: Background models used in LongSpine

Ontology Description Role in LongSpine
Resource Description Framework (RDF) The fundamental data model used for Semantic Web and Linked Data applications. It models objects and relations. Required for any RDF-based system
RDF Schema (RDFS) A schema on top of RDF for modelling types of things and specailisations Required for most RDF-based systems
Web Ontology Language (OWL) An extension to RDFS that uses set theory to describe detailed relationships between things Allows for nuanced classes of object, like different Organisations
Dublin Core Terms A vocabulary of basic annotation properties for things like title, description, source, created date etc. Allows for basic annotations on many LongSpine objects
schema.org A large, general-purpose, OWL model of common classes of objects and relations Used for basic object types like Person and properties like birthDate
Time Ontology in OWL (TIME) An OWL ontology of temporal concepts, for describing the temporal properties of resources Used for all LongSpine real-world temporality
The Dataset Catalogue Vocabulary (DCAT) An OWL ontology designed to facilitate interoperability between data catalogs published on the Web Used to describe LongSpine Datasets at the whole-of-dataset level
Vocabulary of Interlinked Datasets (VoID) An OWL ontology for expressing metadata about RDF datasets, particularly relations between them Used primarily for its definition of a Linkset
The Organization Ontology (ORG) An OWL core ontology for organizational structures Used as the basis for LongSpine organisations modelling
Simple Knowledge Organization System (SKOS) An OWL model for expressing the basic structure and content of concept schemes such as thesauri, classification schemes, subject heading lists, taxonomies, folksonomies Used to structure the vocabularies and thesauri of government functions
LocI A profile of several ontologies implemented to govern Linked Data resources published within the LOC-I project. Used for its overall structure of a Semantic Web-based spine. The LocI Ontology extends DCAT Dataset and VoID Linkset definitions

The models above build on each other with last model listed, LocI, being an integrator of many of the others. Due to the reuse of the LocI ontology, Datasets and Linksets in LongSpine are structured identically to those in the Location Index, even though their content is very different. This does mean that structurally, LongSpine is interoperable with LocI.

All of these models are loaded into the LongSpine Cache as a series of Named Graphs which means, like individual Datasets and Linksets, they can be selected for use, or excluded, within individual queries against the Cache.

§ Component Data Models

Each LongSpine component Dataset has its own data model - ontology - to formally describe its content in a manner that aligns with the LongSpine Overarching Model several existing Australian government datasets. The 5 component data models are:

  1. Administrative Arrangement Orders (AAO) Ontology
  2. AU Org Ontology — for the Australian Government Organisations Register (AGOR)
  3. Commonwealth Record Series (CRS) Ontology
  4. Portfolio Budget Statements (PBS) Ontologynot online yet
  5. Records Disposal Authority (RDA)

See the Data Page for links to the data of the Datasets built according to these models.

§ Vocabularies

In addition to the data models listed above, models of government functions used by LongSpine are presented as regular SKOS vocabularies, meaning SKOS vocabularies without any special properties.

  1. Australian Government Interactive Functions Thesaurus (AGIFT) - existed before LongSpine
  2. Commonwealth Record Series Thesaurus (CRS-Th)
  3. Classifications of Functions of Government (COFOG) - existed before LongSpine
  4. Classifications of Functions of Government - Australia (COFOG-A)