Foaf is a well-known semantic web practice on the Web, and we know that there are millions of FOAF instances on the Web. A scutter can help use to recursively find foaf documents online using hyperlinks in foaf documents; however, how to obtain the initial seeds is still a big issue.
In addition, many semantic web users would like to find out the population of ontology, e.g. the instances of a defined class such as foaf:Person, or where foaf:email has been populated as predicate.
Therefore, Swoogle provide an interesting interface supporting finding instances of a class such as foaf:Person.
This swoogle query searches the usage of a semantic web term, foaf:Person.
Its result consists of six exclusive categories:
- definesClass: the term has been defined as a class in the ontology
- definesProperty: the term has been defined as a property in the ontology
- populatesClass: there is a class-instance of that term in the document
- populatesProperty: the term has been used as a predicate (i.e. populated) in the document
- usesClass: the term has been used (neither defined or populated) as a class in an document. e.g. when an ontology asserts myns:Person rdfs:subClassOf foaf:Person.
- usesProperty: the term has been used as a property
Note that a document might have multiple usage relation with a term, e.g. a document both defines a term as a class, uses it to define other classes and properties, and populates its class-instances.
How to get there
In order to access that page, please follow the following steps:
- start from swoogle home page, choose “search term”
- type the localname or the entire URI surrounded by double qoute, and move to search result page
- click “metadata” link under your URI, and move to term’s metadata page
- click “related documents” link (a grey block) on the top of the page, and move to the wanted page
NOTE: advanced users may use swoogle web service APIs to retrieve more results.