VoiD creation / suggestion extension for OntoWiki edit this file

VoID is an RDF Schema vocabulary for expressing metadata about RDF datasets. It is intended as a bridge between the publishers and users of RDF data, with applications ranging from data discovery to cataloging and archiving of datasets.

Presentation slides: http://bit.ly/void-ontowiki

This extension should be able:

• to generate VoID statements automatically where possible, and
• to suggest additional content based on a suggestion-list

The following prefixes are used in this document:

@cc:       <http://creativecommons.org/ns#>
@dc:       <http://purl.org/dc/elements/1.1/>
@dcterms:  <http://purl.org/dc/terms/>
@foaf:     <http://xmlns.com/foaf/0.1/>
@rdfs:     <http://www.w3.org/2000/01/rdf-schema#>
@void:     <http://rdfs.org/ns/void#>
@wv:       <http://vocab.org/waiver/terms/>

Generated Content

Statistics

void:classes

SPARQL query:

SELECT (COUNT(DISTINCT ?o) AS ?no) WHERE {
  ?s a ?o .
}

void:distinctObjects

SPARQL query:

SELECT (COUNT(DISTINCT ?o) AS ?no) WHERE {
  ?s ?p ?o .
}

void:distinctSubjects

SPARQL query:

SELECT (COUNT(DISTINCT ?s) AS ?no) WHERE {
  ?s ?p ?o .
}

#### void:entities

SPARQL query:

SELECT (COUNT(DISTINCT ?s) AS ?no) WHERE {
  ?s a [] .
}

#### void:properties

SPARQL query:

SELECT (COUNT(DISTINCT ?p) AS ?no) WHERE {
  ?s ?p ?o .
}

void:triples

SPARQL query:

SELECT (COUNT(*) AS ?no) {
  ?s ?p ?o .
}

#### void:vocabulary

To be retrieved via OntoWiki.

Hosting / Feature description

#### void:dataDump

To be retrieved via OntoWiki.

void:feature

List of available RDF searializations to be retrived via OntoWiki.

#### void:openSearchDescription

To be retrieved via OntoWiki.

void:sparqlEndpoint

To be retrieved via OntoWiki.

void:subset

List all named graphs in a given OntoWiki dataset.

void:uriLookupEndpoint

To be retrieved via OntoWiki.

void:uriSpace

To be retrieved via OntoWiki.

Linksets

Suggested Content

The suggested content is based on the recommendation from the VoID specification for dataset metadata. For each item there are listed synonym sets (synset) of RDF properties, in which one property is designed as the preferred property and the rest are the alternatives. The extension checks if one of the properties in a set has a value for a particular dataset. If no value is found, the extension suggests to add it for the preferred property from a set.

Example representing the dataset

• Preferred property: void:exampleResource

### Licence

• Preferred property: cc:license
• Alternative properties:
  • dc:rights
  • wv:norms
  • wv:waiver

SPARQL query:

PREFIX cc: <http://creativecommons.org/ns#>
PREFIX dc: <http://purl.org/dc/elements/1.1/>

ASK {
  { ?s cc:license ?licence }
  UNION
  { ?s dc:rights ?licence }
}

Creator

* Preferred property: dcterms:creator

• Alternative properties:
  • dc:creator
  • dcterms:contributor

SPARQL query:

PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX void: <http://rdfs.org/ns/void#>

ASK {
 ?s a void:Dataset .
 { ?s dc:creator ?creator }
 UNION
 { ?s dcterms:creator ?creator }
 UNION
 { ?s dcterms:contributor ?creator }
}

Description

• Preferred property: dcterms:description
• Alternative properties:
  • rdfs:comment

Publisher

• Preferred property: dcterms:publisher

Source of the dataset

• Preferred property: dcterms:source

Date

• Preferred property: dcterms:date

Date of issue

• Preferred property: dcterms:issued

Date of modification

• Preferred property: dcterms:modified

Highly suggested

Title

• Preferred property: dcterms:title
• Alternative properties:
  • dc:title
  • rdfs:label

SPARQL query:

PREFIX dc: <http://purl.org/dc/elements/1.1/>
PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX void: <http://rdfs.org/ns/void#>

ASK {
  ?s a void:Dataset .
  { ?s dcterms:title ?title }
  UNION
  { ?s dc:title ?title }
}

Date created

• Preferred property: dcterms:created

Nice To Have

#### Homepage of the publisher

• Preferred property: foaf:homepage

#### Root resource

• Preferred property: void:rootResource

Subject described by the dataset

• Preferred property: dcterms:subject
• Alternative properties:
  • dc:subject
  • foaf:primaryTopic

#### URI pattern of the dataset

• Preferred property: void:uriRegexPattern