hide the stack:toward usable linked data

HidetheStack:TowardUsableLinkedData

A.‐S.Dadzie1,M.Rowe2&D.Petrelli3

1.TheOAKGroup,Dept.ofComputerScience,TheUniversityofSheffield

2.TheKnowledgeMediaInsPtute,TheOpenUniversity3.Art&DesignResearchCentre,SheffieldHallamUniversity

KeyMessage•  LinkedData

–  connecPonsbetweendisparate,independent(albeitrelated)data–  renderingpublicinterestdataaccessible

•  allowinghiddeninformaPontobediscoveredmoreeasily

•  enablingquesPonstobeansweredmorefully

•  PotenPalwidelyrecognised,but–  verylarge‐scale,wide‐coverage,highlyinter‐linkeddatarepositories–  under‐uPlisedoutsideSemanPcWebcommunity

•  Aimsoftheresearch–  explorenewmethodsforpresenPngLinkedDatatowideraudience

–  supportmoreintuiPveexploraPonandknowledgeretrieval–  encouragewiderusebyweb‐savvybutnon‐technicalusers

Outline

•  Challenges

•  IllustraPveScenario

•  ExisPngWork•  Approach

•  IniPalEvaluaPon•  Conclusions&NextSteps

•  Acknowledgements

Outline

•  Challenges

•  IllustraPveScenario

•  ExisPngWork•  Approach

•  IniPalEvaluaPon•  Conclusions&NextSteps

•  Acknowledgements

ChallengesinLinkedDataConsumpPon

1.  CombaPnginformaPonoverload2.  ExploraPonstarPngpoint3.  Returningsomethinguseful

4.  EnablinginteracPon

HowcanwemakeLinkedDatausabletoreal,endusers?

•  whereendusersbroadlyclassifiedintooneof:–  SemanPcWebexperts

–  web‐savvybutnon‐technical

Outline

•  Challenges

•  Illustra.veScenario

•  ExisPngWork•  Approach

•  IniPalEvaluaPon•  Conclusions&NextSteps

•  Acknowledgements

Sampledataset‐Data.dcs•  researchgroupsinDCS,UniversityofSheffield•  ontologies(re)used

–  FOAF,PRV,SWRC,BIB•  byLinkedDatastandardsverysmall

–  over8000statements–  ~3000(disPnct)graphnodes–  howeversPllhighlightsthescaleofthechallengesfaced

Scenario

•  InformaPon‐seekingscenario

–  enduser:aprimaryschoolteacher

–  task:lookingforresearchinlocaluniversityon‘WebTechnology’

–  toolstypicallyusedforinformaPonseekingacPviPes:•  websearch/browse•  library

•  considertheuniversitydepartment’swebsitebuiltontopofData.dcs

Outline

•  Challenges

•  IllustraPveScenario

•  Exis.ngWork•  Approach

•  IniPalEvaluaPon•  Conclusions&NextSteps

•  Acknowledgements

ToolsforconsumingLinkedData

•  SemanPcWebuser–  wellcateredfor–  typicaltasks

•  browsingRDF•  validaPngdataandmodels

•  extracPngdatausingformalquerysyntax

•  mainstreamwebuser–  lowertoolsupport–  typicaltasks‐exploratoryinformaPonseeking

•  searchandquery(usinglessformalmethods,e.g.,forms)

•  browsingtodiscoverinformaPon

•  sharingofinformaPondiscovered,resultsofanyanalysis

ToolsforconsumingLinkedDataToolType ExamplesofTools

formadedtextdisplayofRDF(e.g.,usingHTMLtables,templates)

Sig.ma,Marbles,URIBurner,Haystack,Tabulator

RDFgraphmodel W3CRDFValidator,SindiceInspector

othergraphvisualisaPon IsaViz,RDFGravity,Cytoscape,RelFinder

otherdomain‐specificvisualisaPon DBPediaMobile,TalisResearchFundingExplorer

ExpectedSkillSet ExamplesofTools

understandingofSWtechnologystack

Sig.ma,Marbles,URIBurner,W3CRDFValidator,RelFinder,Tabulator

formalquerying,e.g.,SPARQL LESS

basictoadvancedknowledgeseeking,exploratorynavigaPon

DBPediaMobile,RelFinder,TalisRFE,IsaViz

webbrowsing(desktop,mobile) LESS,DBPediaMobile

See also: • Dadzie, A.-S. & Rowe, M. (In press). Approaches to Visualising Linked Data: A Survey, the Semantic Web Journal — Special Call for Survey articles on Semantic Web topics. • Katifori, A., Halatsis, C., Lepouras, G., Vassilakis, C. & Giannopoulou, E. (2007). Ontology visualization methods — a survey, ACM Computing Surveys.

Outline

•  Challenges

•  IllustraPveScenario

•  ExisPngWork•  Approach

•  IniPalEvaluaPon•  Conclusions&NextSteps

•  Acknowledgements

ATemplate‐basedSoluPon

•  takingadvantageofself‐describingRDFdata–  lookupclassofagivenresource–  loadtemplatebasedonclass–i.e.,rdf:typeoftheinstance

•  focusonperPnentinformaPoninadataset

•  highlightrelaPonshipswithindata•  allowenduserstoretrievedetailinROIs(regionsofinterest)

•  combinetemplateswithinformaPon/knowledgevisualisaPon

–  hidethecomplexityoftheunderlyingdata–  removetheneedforspecialistSWknowledgeorskill

Whythisapproach?•  Templates

–  valueseeninthewideuseofFresnellensesandothertemplatedevelopmenttoolsandlanguages,e.g.,IsaViz,LENA,LESS

–  simplicity,reusability,extensibility,flexibility

•  VisualisaPon–  overviewtosupportdetecPonofdatastructure

•  exploratoryinformaPonseeking

•  idenPfying/highlighPngrelaPonships•  recognisinganomalies,errors

–  reducPonincogniPveload–throughadvancedhumanpercepPon•  especiallyusefulforanalysisoflarge,complexdata

TemplateDesign

•  idenPfykeyconcepts&relevantmetadatatodefinetemplates–  matchtostandardontologies,e.g.,FOAF,PRV,SWRC,BIB

–  SPARQLqueries–builtbasedonFresnellensSPARQLselectors

•  presentaPonmethods–  visualoverview‐node‐linkgraph

•  collapseinformaPonrelatedtokeyconceptsintocompoundnodes

•  filteroutlessimmediatelyrelevantdata–providemoreroomforROIs

–  visualencoding•  colourcodingbasedonRDFtype(nodesandlinks)•  iconsbasedonRDFtype(nodes)•  sizetoencodenodeproperPes,e.g.,no.ofoutlinks

–  detailview•  textandthumbnails/icons

Data.dcstemplates

•  mainconcepts–  Organisa.on[<http://xmlns.com/foaf/0.1/Group>]

–  Person [<http://xmlns.com/foaf/0.1/Person>]

–  Publica.on [<http://zeitkunst.org/bibtex/0.1/bibtex.owl#Entry>]

•  informaPonofmaininterest–keyconcepts–  organisaPonalstructure‐researchgroups–  people–  relaPonshipswithinstructure

Challenge1:Comba.nginforma.onoverload

•  verylargeamountsofdistributed,heterogeneousdata

•  highinter‐linking

Data.dcs–RDFgraph

DrawnusingSindiceInspector–first1000triplesonlyforusabilityreasons

Data.dcs‐RDFTextvsBasicGraph

Data.dcs–TemplateGraphView

Challenge1:SoluPonProposed

•  Comba.nginforma.onoverload–  verylargeamountsofdistributed,heterogeneousdata

–  highinter‐linking

•  oursoluPon:–  visualoverview+filters–  highlighPngkeyrelaPonships–  detailview

•  focusongraphROIwithincontextofsurroundingdata+textdetail&thumbnailsorrepresentaPveicons

•  SWusers–  mayhaveaspecificURItoexplore

•  mainstreamusers–  mayormaynothaveaspecificstarPngpoint

–  onenstartwithavagueideaandbrowsetofindifthereisanythinginteresPng

Challenge2:Explora.onstar.ngpoint

Designideas:Detailtemplates

Challenge2:SoluPonproposed

•  Explora.onstar.ngpoint–  SWusers

•  mayhaveaspecificURItoexplore

–  mainstreamusers•  mayormaynothaveaspecificstarPngpoint

•  onenstartwithavagueideaandbrowsetofindwhattheywant

•  oursoluPon:–  supportboth

•  whereinput,specificURIasfocusatstart•  extractlistofpotenPalstartpoints

–  selectedfromkeyRDFtypesinadataset

–  randomlychosenfocus–influencedbycontext

•  centregraphonfocus

•  whatistheenduserlookingfor?

•  howcanwepresentthedatasotheyareabletofindit?

Challenge3:Returningsomethinguseful

Data.dcs–RDF/XML

Co‐ordinatedTemplateViews

Co‐ordinatedTemplateViews

UndertheHood‐DetailView

•  e.g.,SPARQLquerytemplateforthefullpublicaPonview

PREFIX foaf: <http://xmlns.com/foaf/0.1/> PREFIX bib: <http://zeitkunst.org/bibtex/0.1/bibtex.owl#>

SELECT DISTINCT ?publicationTitle ?year ?bookTitle ?personUri ?author ?imageUri

WHERE { <data.dcs:publicationUri> bib:title ?publicationTitle ; bib:hasYear ?year ;

bib:hasBookTitle ?bookTitle ; foaf:maker ?personUri . ?personUri foaf:name ?author ; foaf:img ?imageUri } ORDER BY DESC(?year) ?publicationTitle

•  Returningsomethinguseful–  whatistheenduserlookingfor?–  howcanwepresentthedatasotheyareabletofindit?

•  OursoluPon–  graphoverview+detailtemplateview

–  reusefamiliarwebbrowserlookandfeel(detail)

–  interacPvegraph•  tosupportexploratorynavigaPon•  retaincontextofsurroundinginformaPon

•  colourcodingtohighlightkeyresourcetypesandrelaPonships

Challenge3:SoluPon

•  OursoluPon–  graphoverview+detailtemplateview

–  reusefamiliarwebbrowsinginteracPon

–  clicktonavigatethroughdata(inbothviews)–  pan+zoomforgraphview

–  filterstoremovelessrelevantinformaPon

Challenge4:Enablinginterac.on

Outline

•  Challenges

•  IllustraPveScenario

•  ExisPngWork•  Approach

•  Ini.alEvalua.on•  Conclusions&NextSteps

•  Acknowledgements

FormaPveEvaluaPon•  atESWC2010‘EssenPalHCIfortheSemanPcWeb’tutorial

–  focusgroupof(14)“expertreviewers”–  assessingusabilityforbothmainstreamandexpertusers

–  trainingtaskandaninformaPonexploraPonexercise

•  graphsfoundtobeexpressive•  graphvieweffecPveingivingasenseofdatadistribuPon

•  detailvieweffecPvelydisplayedkeyresources“inaneatandconciseway”

•  prototypeseentohavepotenPalforexploringanddebuggingLD

•  somedifficultyforusersnotfamiliarwithinteracPvegraphlayout–  “eventuallyyougotabigpictureofthedata’’–  “IlikedthedirectmanipulaPonbutthegraphshouldstayput

[whenIclick]”

Outline

•  Challenges

•  IllustraPveScenario

•  ExisPngWork•  Approach

•  IniPalEvaluaPon•  Conclusions&NextSteps

•  Acknowledgements

Conclusions

•  exploredhuman‐centredsoluPonforconsumingLinkedData–  exploiPngtemplates(viaSWtechnology)–  combinedwithvisualisaPon

•  evaluaPonhighlightedchallengessPllremaining‐amongothers:–  scale–  complexity

•  however–promisingstart....•  NextSteps

–  moreusercontrol‐(intuiPve)supportfordefiningtemplates,filters–  dynamicupdatewithnewLinkedData–  formalusabilityevaluaPonwithwiderrangeofusers

Outline

•  Challenges•  IllustraPveScenario

•  ExisPngWork

•  Approach•  IniPalEvaluaPon

•  Conclusions&NextSteps

•  Acknowledgements–  parPcipantsofESWC2010‘EssenPalHCIfortheSemanPcWeb’tutorial–  Funding

•  A‐SDadzie–SmartProducts&WeKnowIt(EUFP7),X‐Media(EUFP6)

•  MRowe–WeGov(EUFP7)

•  DPetrelli–X‐Media(EUFP6)

HidetheStack@SWDogfood