publishing and interacting with linked data

Publishing and Interacting with Linked Data

Roberto Garcia, Josep Maria Brunetti, Antonio López-Muzás, Juan Manuel Gimeno, Rosa Gil

WIMS’11 Conference, May 25th 2011, Sogndal, Norway

HCI & Data Integration Research GroupUniversitat de Lleida, Spain

http://creativecommons.org/licenses/by/3.0/

Overview

• RhizomerPlatform for Linked Data publishing (also Semantic Data)–Data access

• Read (LinkedData / SPARQL) • Write (Semantic FORMS + HTTP PUT/POST/DEL)

–Data sources• Jena (File, MySQL, Postgres), Virtuoso, OWLIM,…

–Interaction• Overview: Navigation bars• Filter: Facets• Details: HTML+RDFa, Interaction Web Services

(map, timeline,…)


Architecture

• Server part:– REST interface over repository

• GET: URI (LinkedData) or SPARQL Query• PUT/POST/DELETE: data management

MetadataStore

Rhizomer

GE

T

PU

T

PO

ST

DE

L

search new edit delete


Architecture

• Scope of GET operations:– Concise Bounded Description (CBD) +

rdfs:labels for all selected resources

• Scope of POST/PUT/DEL operations:– Concise Bounded Description

• DESCRIBE queries by default– Facilitate browsing heterogeneous data– Without a priori knowledge


http://rhizomik.net/~rosa

http://...vcard#ADR

http://...vcard#StreetJaume II, 69

http://...vcard#Locality

Lleida

http://...onto#affiliation

http://www.udl.cat

http://...rdf#type

http://...rdfs#label

Rosa Gil

http://...rdf#type

http://...onto#Professor

http://...rdf#type

http://...vcard#work

http://...onto#University

Architecture

• DESCRIBE http://rhizomik.net/~rosa: CBD(…~rosa) = Fragment A U rdfs:labels

Fragment A


Architecture

RDF2HTML

GET RDF2HTML

<s5t:Audio rdf:about="http://www.segre.com/audio/20070323-bm.mp3"> <dc:title>Butlletí Migdia</dc:title> <dc:date>2007-03-23</dc:date> <s5t:genre rdf:resource="&srs;11000000"/> <s5t:transcriptResource> http://www.segre.com/audio/20070323-bm.xml </s5t:transcriptResource></srt:Audio> http://www.segre.com/ audio/ 20070323-bm.mp3 a Audio

title Butlletí Migdia

date 2007-03-23

genre politics

transcript http://www.segre.com/audio/20070323-bm.xml

Referrers

http://rhizomik.net/.../NewsCodes-SubjectsOnto#11000000 a Subject

label politics

descriptionLocal, regional, national and international exercise of power, or struggle for power, and the relationships between governing bodies and states.

Referrers


http://www.segre.com/audio/20070323-bm.mp3

http://www.segre.com/audio/20070323-bm.mp3

Interacting

• Until now, Rhizomer like other Linked Data publishing tools…– HTML+RDFa and content negotiation– Useful for computers, but also for human users?

• User tests:– Typical questions:

• Where do I start? • Where do I go now?• What is this data about?

– What do we offer? • Text search, type URI, SPARQL query,…

…but they do not answer end-users needs


Interacting

• Example: What to do with DBPedia? – 3.5 million things described

• Ontology: 257 classes y 1276 properties


Interacting

– DBPedia main page does not provide too many clues...


Interacting

• SPARQL Endpoint:– select distinct(?c) (count(?i) as ?n)

where {?i a ?c} order by desc(?n)

c n

http://www.w3.org/2002/07/owl#Thing 1668503

http://www.w3.org/2004/02/skos/core#Concept 632607

http://www.opengis.net/gml/_Feature 571764

http://dbpedia.org/ontology/Place 462349

http://dbpedia.org/ontology/Person 363751

http://dbpedia.org/ontology/Work 355100

http://dbpedia.org/ontology/PopulatedPlace 340443

http://dbpedia.org/ontology/Settlement 304370

http://xmlns.com/foaf/0.1/Person 296595

http://dbpedia.org/ontology/Species 168575WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interacting

• Simple search– What to type?

– A URI? URI label?

– …


Interacting

• Advanced search:– iSparql


Information Architecture

• Proposal: adapt data interaction patterns [Shneiderman] and Information Architecture components [Morville]– Data structure: automate IA components

– Scalable, dataset independent

• Interaction Patterns / IA Components– Overview --> navigation bars, site map

• Main classes (topics) and their organisation

– Zoom & Filter--> facets, breadcrums• Main properties and values, filter

– Details --> HTML view, Object-Action Paradigm


AI Components Navigation Bars

– Get hierarchical structure for dataset ontologies

– For each class• URI

• Label

• # instances

• Subclasses list

– Flatten to desired # levels and elements / level• Classes and namespaces whitelist and blacklist

– Algorithm:• When there is room, divide class with most instances

• When too many options, group classes with less instances



7 elements in “Species” submenu:



Navigation bar provides overview for DBPedia… …but what to do with 12.334 birds now?


AI Components Facets

• Pre-compute list of facets for each class– Properties used in dataset instances descriptions– Facet metrics: frequency, #different values, more

common value cardinality, entropy,…

• DBPedia Birds case:– http://dbpedia.org/ontology/Bird 12334 instances– 226 different properties

• http://dbpedia.org/ontology/kingdom, 100%, 3 values, 6846 (Animalia),…

• User unfolds facet, show 5 +common values– Filter, get more…



• Order facets by "utility” (work in progress):– Prefer common properties, high frequency

– For values cardinality, discard extreme cases: • Just 1 value for the property

• All different values, i.e. max. value cardinality = 1

– Prefer properties that evenly divide results, higher entropy

Property Entropy Value InstanceshasFlavor 0.918434 Moderate 28

Strong 15Delicate 10

hasSugar 0.556416 Dry 43Sweet 6OffDry 4

Wine (Wine Ontology)


InteractionObject-Action



• Given a resource (object)…determine available services (actions)

• Services descriptions:– endPoint: service location– hasInput: ASK SPARQL Query Template

• Service applicable to any resource ASK is true

– hasOutput: output content type


Conclusions

• Navigation menus – dataset classes (topics) overview

• Facets – per class properties and values overview, filter

• Details – Generic view (HTML) + specific (map, timeline…)

• Users build queries without SPARQL or dataset structure knowledge


Future Work

• Facets: – type dependent facets (number ranges, dates,…),

inverse properties, facets for facet values,…

• Other IA components: sitemap, breadcrumbs,…

• Assisted metadata edition– Recommend properties and values based on

available ontologies and values

• More interaction services– Calendar– Plot…


Thank you for your attention

More details: http://rhizomik.net/rhizomer

Contact: Roberto Garcia ([email protected])

HCI & Data Integration Research GroupUniversitat de Lleida, Spain

http://rhizomik.net/rhizomer

mailto:[email protected]

http://creativecommons.org/licenses/by/3.0/

publishing and interacting with linked data

Documents

norwaywims11 conference

spainwims11 conference

propertieswims11 conference

knowledgewims11 conference

referrers wims11 conference

rosa gilwims11 conference

referrers http

sparql queryputpostdelete