DBpedia Archivo

Archivo is an online ontology interface and augmented archive, that discovers, crawls, versions and archives ontologies on the DBpedia Databus. Each Databus Artifact represents one certain ontology and each version represents a new version of the ontology.

Use Cases

• Ontology-Backup: From time to time ontologies are unavailable at their usual location in the web. In this case Archivo can be used as a simple backup to prevent failure of services.
• Testing & Rating: Archivo runs some test to check the usability of a ontology, for example parsing, licenses or consistency. For this Archivo introduced a star-rating. Check out http://archivo.dbpedia.org/info for a detailed view of the versions of each ontology with the test results.

Accessing an Ontology (Version) via Archivo

Simple

To download the latest version use

http://archivo.dbpedia.org/download?o={ontology-URI}&f={file-extension}

and Archivo redirects to the latest version that is backed up.

The format can be set by using f={ttl,owl,nt} (optional, default: owl) or by setting the Accept-Header (first one overwrites the latter).

Example: curl -L "http://archivo.dbpedia.org/download?o=http://advene.org/ns/cinelab/ld&f=ttl" downloads the latest version of the Cinelab ontology as Turtle file.

Advanced

By using a GET request with the implemented formats (application/rdf+xml, application/n-triples or text/turtle) as Accept-Headers returns all information about all versions of this URI as RDF.

Browse, Find and Search Ontologies included in Archivo

There are multiple options to find an ontology (snapshot):

• Here is a complete list of all ontologies in Archivo with their Databus Artifact and the URL of the latest Turtle-File of each.
• Enter your ontology-URI here and you get information about all the versions of the ontology archived in Archivo.
• Check out the the handy collections on the DBpedia Databus:
  • A collection of the latest original files: here
  • A collecttion of the latest parsed files: here

Adding an Ontology to Archivo

Ontologies can be added to Archivo using the add-service of the frontend. But the ontology must fulfill two requirements to be added:

• The URI must be accessible and the RDF content of the ontology must be reachable via content negotiation from there in any of these formats: RDF+XML, N-Triples, Turtle
• The URI defined in the a owl:Ontology (or skos:ConceptScheme) triple must be the same as the one provided here. If that's not the case Archivo tries to handle the new URI just like the one entered.

Star Rating

Archivo provides a basic star-rating (not to be confused with the 5 stars of linked data).

Baseline: The minimum requirements a Ontology should fulfill.

• All of the following criteria have to be fulfilled:

  1. The non-information URI resolves to a machine readable format or a machine readable version of the ontology is deterministically discoverable by other common means.
  2. Download was successful
  3. Uses a common format implemented by Archivo (rdf+xml, turtle or n-triples)
  4. At least one format was found that parses with no or few (negligible) syntactical warnings

• A proper ontology declaration was found using rdf:type owl:Ontology and some form of license could be detected. A high degree of heterogeneity is permissible for this star regarding the used property/subproperty as well as object:license URI (resolvable linked data or web link),xsd:stringorxsd:anyURI

If the ontology fulfills the baseline, it can earn two further stars by using good practises:

• We require a homogenized license declaration using dct:license as object property with a URI (not string or anyURI).

• We measure the compatibility with currently available reasoners such as Pellet/Stardog (more to follow) and run available tasks such as consistency checks and classification.

Archivo Documentation

Augmentation Files (on the Databus)

Archivo provides for each version different files:

type-values	sub-cvs	Explaination
orig		Snapshot of the original ontology file
parsed		Files parsed by rapper, available as owl, nt and ttl
OOPS		OOPS-report
generatedDocu		human readable documentation by LODE
profile		a profile check done by profilechecker
shaclReport	validates={minLicense, goodLicense, lodeMetadata}	shacl-report as turtle file
meta		a JSON file containing some meta info
pelletInfo	imports={FULL,NONE}	the pellet info report, with and without imports
pelletConsistency	imports={FULL,NONE}	the pellet consistency report, with and without imports
diff	axioms={old,new}	These file contain the added/deleted triples

Ontology Sources

Archivo uses four different sources to find potential ontologies:

1. Ontology Repositories: e.g ontologies listed in LOV
2. Subjects, Predicates and Objects of Ontologies: Every SPO in an Ontology can lead to a potential new ontology, so Archivo can discover new vocabularies by analyzing already listed ontologies
3. VOID Data: Search for new ontologies by looking at VoID metadata summaries describing used classes and properties (on the DBpedia Databus)
4. User Suggestions