Publishing, Linking and Annotating Events via Interactive Timelines: an Earth Sciences Case Study

1. Publishing, Linking and Annotating Events via Interactive Timelines:an Earth Sciences Case Study Jane Hunter, Lianli Gao eResearch Lab School of ITEE, The University of Queensland

2. Overview • Background & Objectives • Case Study • Related Work • Methodology • Ontologies • System Implementation • Evaluation • Future Work • Conclusions

3. Background • Multi-disciplinary – scientists, historians, museum curators, anthropologists • Interested in temporal, causal relationships between events • Support integration/aggregation/correlation of events from different regions/sources/disciplines • Linked Data approach • Enable search, query, visualization via timelines • Enable semantic annotation of events & temporal relationships between them - via timelines

4. Case Study • Geo-scientists - natural disaster events • Earthquakes, tsunamis, volcanic eruptions • Movement at plate boundaries -> volcanic eruptions, • earthquakes -> tsunamis • Need to understand time delays/temporal relationships • Better predictive models & disaster warning systems

5. Objectives • Common model/ontology for describing: • geochange events – extend an event model • timelines – group “events” via URIs • Enable interoperability between timelines • Separate presentation from content • relationships between them • Develop a tool to enable semantic annotation of events via an interactive timeline interface • Add further information & interpretation • Enable reasoning across the events e.g., to infer “causality” or “isResultOf” properties

6. Related Work • Event ontologies: ABC, CIDOC/CRM, DOLCE+DnSUltralite (DUL), Event-Model-F, OpenCYC, LODE (Linking Open Descriptions of Events) • Timelines– SIMILE, MyTimelines, TimelineBuilder, xtimeline, Timelinr, WikiTimeLine, TimeGlider • No interoperability, events are embedded • Timeline Ontology (Raimond & Abdallah) – for the music domain • Event annotation via timelines – Google Interactive Charts, RecordedFuture, ChronoViz, Chronozoom • Events & annotations are not independent Web resources

7. Methodology • Developed ontologies:events, timelines, annotations, temporal relationships; • Harvested event data - NOAA National Geophysical Data Center’s (NGDC) Natural Hazards Data, USGS Earthquake Database etc … • Represented it in our event model and stored this data in our own RDF triple store, generating HTTP URIs for each event • Published the RDF triples to the the Comprehensive Knowledge Archive Network (CKAN) Linked Data Hub; • Developed a SPARQL interface to our RDF triple store to enable users to search, retrieve and display events based on metadata terms and keywords, and display them on a SIMILE Timeline • Developed Annotation sidebar to Firefox (SAFE): • Annotate a single event on single timeline; • Annotate multiple events on single timeline or within a time period; • Annotate multiple events on different timelines displayed simultaneously; • Annotate relationships between events on same timeline or different timelines; • Store annotations on an annotation server – searched, browsed • Evaluation – quantitative and qualitative

8. System Architecture

9. startTime endTime Ontologies title Timeline intervalUnits description references URI atPlace Event title atTime description source subClassOf subClassOf subClassOf Tsunami Volcanic Eruption Earthquake noDeaths noDeaths volcanoName noDeaths speed focalDepth waterHeight explosivityIndex volcanoType magnitude intensity

10. Temporal Relationships • time:before/time:after – one event precedes/follows another; • time:intervalOverlaps – the duration of two events overlaps; • time:intervalEquals – the start and end times of two events coincide; • time:intervalMeets – the end of one event coincides with the start of another event; • time:intervalContains – one event starts and finishes within the duration of a second event

11. Semantic Relationships • isRelatedTo– precise relationship between events is unclear, unknown • requires/requiredBy – one event cannot occur unless the previous event has occurred/begun • causes/causedBy – one event E2 is caused by another event E1 • Only valid if E1 before E2 – system checks this before allowing tag to be saved

12. Applying the OAC Model

13. Applying the OAC Model

14. SPARQL Querying of Events/Timelines Query and Retrieve Events from RDF TripleStore

15. Annotation of Single Event

16. Annotating a set of events

18. Evaluation • SEAS sidebar • Efficiency – time to complete set tasks • Used screen capture software to analyse users actions • Usability – user survey – response on 5pt Likert scale • “The SAFE sidebar is easy to download and install” • “The interface for creating new annotations is easy to use” • “The suggested tags were complete, relevant and unambiguous” • “The search results returned what I expected” • Ontologies – complete, correct • Events • Timelines • Temporal & Semantic relationships

19. Results of Timed Tasks

20. Results • Add new subclass of event – runup • Extend query interface • Give me all events that are part of causal relationships? • SMIL is XML-based – plan to develop own timeline tool that reads RDF (timeline & event data) • Geo-change events – spatio-temporal – enable annotation of events displayed on map & timeline • Spatial relationships – inside, surrounds, neighbourOf • Temporal relationships – before, after, coincides • Spatio-temporal relationships – what are they? • SWRL inferencing rules • If ((E1 -> causes ->T1)&&(T1 ->causes-> R1) then E1 ->causes ->R1 • How many deaths were caused by E1?

21. Conclusions • Event model can be extended to describe real-world geo-change events • Timeline ontology – necessary to support interoperability between timeline tools and to separate events from timelines • OAC ontology- can be extended to support temporal relationship annotations between multiple events (need to use rdf:Seq) • SEAS – simple, easy-to-use, efficient, novel tool for interactive annotation of events via timelines (SMIL)

22. Questions? Contacts • Lianli Gao: l.gao1@uq.edu.au • Jane Hunter: j.hunter@uq.edu.au http://itee.uq.edu.au/~eresearch http://seas.metadata.net/events/ http://ckan.net/package/geochangeevents