Publishing and Interacting with Linked Data Roberto Garcia, Josep Maria Brunetti, Antonio López-Muzás, Juan Manuel Gimeno, Rosa Gil WIMS’11 Conference, May 25 th 2011, Sogndal, Norway HCI & Data Integration Research Group Universitat de Lleida, Spain

Overview Rhizomer Platform 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,…) WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Architecture Server part: –REST interface over repository GET: URI (LinkedData) or SPARQL Query PUT/POST/DELETE: data management Metadata Store Rhizomer GET PUT POST DEL search new edit delete WIMS’11 Conference, May 25th 2011, Sogndal, Norway

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

Architecture DESCRIBE CBD(…~rosa) = Fragment A U rdfs:labels Fragment A WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Architecture RDF2HTML GET  RDF2HTML Butlletí Migdia audio/ bm.mp3 a Audio titleButlletí Migdia date genrepolitics transcripthttp:// Referrers a Subject labelpolitics description Local, regional, national and international exercise of power, or struggle for power, and the relationships between governing bodies and states. Referrers WIMS’11 Conference, May 25th 2011, Sogndal, Norway

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

Interacting Example: What to do with DBPedia? – 3.5 million things described Ontology: 257 classes y 1276 properties WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interacting – DBPedia main page does not provide too many clues... WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interacting SPARQL Endpoint: – select distinct(?c) (count(?i) as ?n) where {?i a ?c} order by desc(?n) cn WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interacting Simple search – What to type? – A URI? URI label? – … WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interacting Advanced search: – iSparql WIMS’11 Conference, May 25th 2011, Sogndal, Norway

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

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

AI Components Navigation Bars 7 elements in “Species” submenu: WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Navigation Bars WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Navigation Bars WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Navigation Bars WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Navigation Bars WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Navigation Bars WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Navigation Bars Navigation bar provides overview for DBPedia… …but what to do with birds now? WIMS’11 Conference, May 25th 2011, Sogndal, Norway

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: – instances – 226 different properties 100%, 3 values, 6846 (Animalia),… User unfolds facet, show 5 +common values – Filter, get more… WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Facets WIMS’11 Conference, May 25th 2011, Sogndal, Norway

AI Components Facets 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 Wine (Wine Ontology) WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interaction Object-Action WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interaction Object-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 WIMS’11 Conference, May 25th 2011, Sogndal, Norway

Interaction Object-Action WIMS’11 Conference, May 25th 2011, Sogndal, Norway

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

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

Thank you for your attention More details: Contact: Roberto Garcia HCI & Data Integration Research Group Universitat de Lleida, Spain