This short article describes a potential use of a bibliographic data set that has been created using the principles of FRBR 1 (Functional Requirements for Bibliographic Records). The FRBR entities and relationships are visualised using the Protovis toolkit2 developed by Stanford University.
The result of experiment can be viewed at this address:
http://bibin.hio.no/~davm/php/sparqling/pode/petterson.html
The data set has been published by the Pode project3 at the Oslo Public Library. Bibliographic data about and by two significant Norwegian authors - Knut Hamsun4 and Per Petteson5 - has been converted from the Norwegain MARC standard (NorMARC) to RDF data that has been subsequently loaded into a triple store.
Under the conversion the records have been split into group one FRBR entities:
The final group one entities - items - are not a part of the data.
The tool for the FRBR conversion has been developed by Trond Aalberg6 of NTNU.
The data has been mapped to RDF predicates using the following vocabularies:
The table describing the mapping of MARC subfields to predicates is available on the Pode blog7.
The data has been loaded into a triple store which is available for SPARQL queries at the following address:
http://bibpode.no/rdfstore/endpoint.php
The force-directed layout visualisation from the Protovis toolkit is used to display. The visualisation consists of nodes and arcs. The nodes represent the FRBR entities (works, expressions and manifestations), while the arcs show the relationships between the entities.
Protovis is a Javascript library which is linked to the HTML page.
The input to the visualisation is a file in JSON format.
PHP scripts query Pode's SPARQL endpoint and create the JSON file.
The first SPARQL query finds all the works that are written by Per Petterson:
PREFIX person: <http://www.bibpode.no/person/>
PREFIX dct: <http://purl.org/dc/terms/>
PREFIX frbr: <http://purl.org/vocab/frbr/core#>
SELECT ?wuri ?wtitle WHERE {
?wuri a frbr:Work ;
dct:creator person:Petterson_Per ;
dct:title ?wtitle .
}
For each work ($workuri) this query will find the expressions that are linked to it:
PREFIX dct: <http://purl.org/dc/terms/>
PREFIX frbr: <http://purl.org/vocab/frbr/core#>
SELECT ?euri ?etitle ?format ?lang WHERE {
<$workuri> frbr:realization ?euri .
?euri a frbr:Expression ;
dct:format ?format ;
dct:language ?lang ;
dct:title ?etitle .
}
Finally for each expression ($expruri) the manifestations that are linked to it are retrieved:
PREFIX dct: <http://purl.org/dc/terms/>
PREFIX frbr: <http://purl.org/vocab/frbr/core#>
SELECT ?muri ?mtitle ?issued WHERE {
<$expruri> frbr:embodiment ?muri .
?muri a frbr:Manifestation ;
dct:title ?mtitle .
optional { ?muri dct:issued ?issued . }
}
The resulting JSON file consists of two parts. Firstly, nodes that have four fields:
petterson = {
nodes:[
{nodeName:"W: Michael/Frank", group:"blue", title:"", adr:"W__Petterson_Per_michael_frank"},
{nodeName:"E: Michael/Frank (Bok / nob)", group:"green", title:"", adr:"E__5ed323e55fb376691c6fd8c24f11c42b"},
{nodeName:"M: Månen over Porten (2004)", group:"red", title:"Månen over Porten ", adr:"M__401e0b78174d64517121b91758ca8c"},
...
Secondly, links that record which nodes (source and target) are connected. Value can be used to display the strength of the connection.
links:[
{source:1, target:0, value: 3},
{source:2, target:1, value: 3},
{source:4, target:3, value: 3},
...
Manifestations can be linked to several expressions. This is the case with a collection of short stories, for example Månen over porten. The red manifestation Månen over porten is surrounded by green expressions that represent the short stories. The red manifestation at the bottom of the group represents The Norwegian feeling for real a collection of short stories that are translated from Norwegian. This collection includes one of the short stories.
An example of a work that leads to many expressions is shown below. The work is Til sibir (To Siberia) that has the following expressions:
The Norwegian book, shown at the bottom right of the cluster, has resulted in two manifestations from 1996 and 2004.
When the mouse hovers over the node short details on the node are shown. Clicking on the node (currently only manifestations) gathers details from relevant sources such as Bookshelf, Libris, LibraryThing (see below), Google Books, OpenLibrary.
Updated: 16-11-2010